NodeAV

node-av / lib / FormatContext

Class: FormatContext ​

Defined in: src/lib/format-context.ts:80

Container format context for reading/writing multimedia files.

Central structure for demuxing (reading) and muxing (writing) media files. Manages streams, packets, metadata, and format-specific operations. Supports both file-based and custom I/O through IOContext. Essential for all file-based media operations.

Direct mapping to FFmpeg's AVFormatContext.

Example ​

typescript
import { FormatContext, FFmpegError } from 'node-av';
import { AVMEDIA_TYPE_VIDEO } from 'node-av/constants';

// Open input file
const ctx = new FormatContext();
let ret = await ctx.openInput('input.mp4');
FFmpegError.throwIfError(ret, 'openInput');

ret = await ctx.findStreamInfo();
FFmpegError.throwIfError(ret, 'findStreamInfo');

// Find video stream
const videoIndex = ctx.findBestStream(AVMEDIA_TYPE_VIDEO);
if (videoIndex < 0) {
  throw new Error('No video stream found');
}

// Read packets
const packet = new Packet();
packet.alloc();
while ((ret = await ctx.readFrame(packet)) >= 0) {
  if (packet.streamIndex === videoIndex) {
    // Process video packet
  }
  packet.unref();
}

// Cleanup
await ctx.closeInput();

See ​

Extends ​

Implements ​

Constructors ​

Constructor ​

new FormatContext(): FormatContext

Defined in: src/lib/format-context.ts:83

Returns ​

FormatContext

Overrides ​

OptionMember<NativeFormatContext>.constructor

Properties ​

native ​

protected native: NativeFormatContext

Defined in: src/lib/option.ts:1059

Inherited from ​

OptionMember.native

Accessors ​

bitRate ​

Get Signature ​

get bitRate(): bigint

Defined in: src/lib/format-context.ts:135

Total stream bitrate.

Bitrate in bits per second. 0 if unknown.

Direct mapping to AVFormatContext->bit_rate.

Returns ​

bigint

duration ​

Get Signature ​

get duration(): bigint

Defined in: src/lib/format-context.ts:123

Duration of the stream.

Total stream duration in microseconds. AV_NOPTS_VALUE if unknown.

Direct mapping to AVFormatContext->duration.

Returns ​

bigint

flags ​

Get Signature ​

get flags(): AVFormatFlag

Defined in: src/lib/format-context.ts:147

Format-specific flags.

Combination of AVFMT_FLAG_* values controlling format behavior (e.g., AVFMT_FLAG_GENPTS).

Direct mapping to AVFormatContext->flags.

Returns ​

AVFormatFlag

Set Signature ​

set flags(value): void

Defined in: src/lib/format-context.ts:151

Parameters ​
value ​

AVFormatFlag

Returns ​

void

iformat ​

Get Signature ​

get iformat(): InputFormat | null

Defined in: src/lib/format-context.ts:241

Input format descriptor.

Format used for demuxing. Null for output contexts.

Direct mapping to AVFormatContext->iformat.

Returns ​

InputFormat | null

maxAnalyzeDuration ​

Get Signature ​

get maxAnalyzeDuration(): bigint

Defined in: src/lib/format-context.ts:179

Maximum duration to analyze streams.

Time in microseconds to spend analyzing streams. Larger values improve stream detection accuracy.

Direct mapping to AVFormatContext->max_analyze_duration.

Returns ​

bigint

Set Signature ​

set maxAnalyzeDuration(value): void

Defined in: src/lib/format-context.ts:183

Parameters ​
value ​

bigint

Returns ​

void

maxInterleaveDelta ​

Get Signature ​

get maxInterleaveDelta(): bigint

Defined in: src/lib/format-context.ts:203

Maximum buffering duration for interleaving.

Specifies the maximum difference between the timestamps of the first and the last packet in the muxing queue, above which libavformat will output a packet regardless of whether it has queued a packet for all the streams.

Set to 0 for unlimited buffering

Default: 10000000 (10 seconds in microseconds)

Muxing only, set before avformat_write_header().

Direct mapping to AVFormatContext->max_interleave_delta.

Returns ​

bigint

Set Signature ​

set maxInterleaveDelta(value): void

Defined in: src/lib/format-context.ts:207

Parameters ​
value ​

bigint

Returns ​

void

maxStreams ​

Get Signature ​

get maxStreams(): number

Defined in: src/lib/format-context.ts:335

Maximum number of streams.

Limit on stream count for security/resource reasons.

Direct mapping to AVFormatContext->max_streams.

Returns ​

number

Set Signature ​

set maxStreams(value): void

Defined in: src/lib/format-context.ts:339

Parameters ​
value ​

number

Returns ​

void

metadata ​

Get Signature ​

get metadata(): Dictionary | null

Defined in: src/lib/format-context.ts:219

Container metadata.

Key-value pairs of metadata (title, author, etc.).

Returns a copy of AVFormatContext->metadata - mutating the returned Dictionary does not affect the context. Assign it back to apply changes.

Returns ​

Dictionary | null

Set Signature ​

set metadata(value): void

Defined in: src/lib/format-context.ts:230

Parameters ​
value ​

Dictionary | null

Returns ​

void

nbPrograms ​

Get Signature ​

get nbPrograms(): number

Defined in: src/lib/format-context.ts:350

Number of programs.

For containers with multiple programs (e.g., MPEG-TS).

Direct mapping to AVFormatContext->nb_programs.

Returns ​

number

nbStreams ​

Get Signature ​

get nbStreams(): number

Defined in: src/lib/format-context.ts:293

Number of streams in the container.

Direct mapping to AVFormatContext->nb_streams.

Returns ​

number

oformat ​

Get Signature ​

get oformat(): OutputFormat | null

Defined in: src/lib/format-context.ts:256

Output format descriptor.

Format used for muxing. Null for input contexts.

Direct mapping to AVFormatContext->oformat.

Returns ​

OutputFormat | null

Set Signature ​

set oformat(value): void

Defined in: src/lib/format-context.ts:264

Parameters ​
value ​

OutputFormat | null

Returns ​

void

pb ​

Get Signature ​

get pb(): IOContext | null

Defined in: src/lib/format-context.ts:279

Custom I/O context.

For custom I/O operations instead of file I/O. Assigning a callback-backed context also sets AVFMT_FLAG_CUSTOM_IO so libavformat never closes it. A context opened with open2() is closed once, by whichever comes first: its closep(), which also clears this pb like avio_closep(&ctx->pb) in C, or closing or freeing this output context. An IOContext can be the pb of one FormatContext at a time.

Direct mapping to AVFormatContext->pb.

Returns ​

IOContext | null

Set Signature ​

set pb(value): void

Defined in: src/lib/format-context.ts:283

Parameters ​
value ​

IOContext | null

Returns ​

void

pbBytes ​

Get Signature ​

get pbBytes(): bigint

Defined in: src/lib/format-context.ts:359

Number of bytes read/written through I/O context.

Direct mapping to avio_tell(AVFormatContext->pb).

Returns ​

bigint

probeScore ​

Get Signature ​

get probeScore(): number

Defined in: src/lib/format-context.ts:371

Format probe score.

Confidence score from format detection (0-100). Higher values indicate more confident detection.

Direct mapping to AVFormatContext->probe_score.

Returns ​

number

probesize ​

Get Signature ​

get probesize(): bigint

Defined in: src/lib/format-context.ts:163

Maximum bytes to probe for format detection.

Larger values improve format detection accuracy but increase startup time.

Direct mapping to AVFormatContext->probesize.

Returns ​

bigint

Set Signature ​

set probesize(value): void

Defined in: src/lib/format-context.ts:167

Parameters ​
value ​

bigint

Returns ​

void

startTime ​

Get Signature ​

get startTime(): bigint

Defined in: src/lib/format-context.ts:111

Start time of the stream.

Position of the first frame in microseconds. AV_NOPTS_VALUE if unknown.

Direct mapping to AVFormatContext->start_time.

Returns ​

bigint

streams ​

Get Signature ​

get streams(): Stream[]

Defined in: src/lib/format-context.ts:304

Array of streams in the container.

All audio, video, subtitle, and data streams.

Direct mapping to AVFormatContext->streams.

Returns ​

Stream[]

strictStdCompliance ​

Get Signature ​

get strictStdCompliance(): number

Defined in: src/lib/format-context.ts:320

Strictness level for standards compliance.

FF_COMPLIANCE_* value controlling how strictly to follow specifications.

Direct mapping to AVFormatContext->strict_std_compliance.

Returns ​

number

Set Signature ​

set strictStdCompliance(value): void

Defined in: src/lib/format-context.ts:324

Parameters ​
value ​

number

Returns ​

void

url ​

Get Signature ​

get url(): string | null

Defined in: src/lib/format-context.ts:95

URL or filename of the media.

For input: the opened file path. For output: the target file path.

Direct mapping to AVFormatContext->url.

Returns ​

string | null

Set Signature ​

set url(value): void

Defined in: src/lib/format-context.ts:99

Parameters ​
value ​

string | null

Returns ​

void

Methods ​

[asyncDispose]() ​

[asyncDispose](): Promise<void>

Defined in: src/lib/format-context.ts:1595

Dispose of the format context.

Implements the AsyncDisposable interface for automatic cleanup. Closes input/output and frees resources.

Returns ​

Promise<void>

Promise that resolves when disposed

Example ​

typescript
{
  await using ctx = new FormatContext();
  await ctx.openInput('input.mp4');
  // Use context...
} // Automatically closed and freed

Implementation of ​

AsyncDisposable.[asyncDispose]

allocContext() ​

allocContext(): void

Defined in: src/lib/format-context.ts:390

Allocate a format context.

Allocates the context structure. Usually not needed as openInput/allocOutputContext2 handle this.

Direct mapping to avformat_alloc_context().

Returns ​

void

Example ​

typescript
const ctx = new FormatContext();
ctx.allocContext();
// Context is now allocated

allocOutputContext2() ​

allocOutputContext2(oformat, formatName, filename): number

Defined in: src/lib/format-context.ts:424

Allocate an output format context.

Allocates and configures context for writing. Format is determined by parameters in priority order.

Direct mapping to avformat_alloc_output_context2().

Parameters ​

oformat ​

OutputFormat | null

Specific output format to use

formatName ​

string | null

Format name (e.g., 'mp4', 'mkv')

filename ​

string | null

Filename to guess format from extension

Returns ​

number

0 on success, negative AVERROR on error:

  • AVERROR_ENOMEM: Memory allocation failure
  • AVERROR_EINVAL: Invalid parameters

Example ​

typescript
import { FFmpegError } from 'node-av';

const ctx = new FormatContext();
const ret = ctx.allocOutputContext2(null, 'mp4', 'output.mp4');
FFmpegError.throwIfError(ret, 'allocOutputContext2');

See ​

clearFlags() ​

clearFlags(...flags): void

Defined in: src/lib/format-context.ts:1398

Clear format flags.

Clears one or more flags using bitwise AND NOT. Allows clearing multiple flags without manually performing bitwise operations.

Parameters ​

flags ​

...AVFormatFlag[]

One or more flag values to clear

Returns ​

void

Example ​

typescript
import { AVFMT_FLAG_IGNIDX } from 'node-av/constants';

// Clear specific flag
formatContext.clearFlags(AVFMT_FLAG_IGNIDX);

See ​

closeInput() ​

closeInput(detachPb?): Promise<void>

Defined in: src/lib/format-context.ts:639

Close an input format context.

Closes input file and releases resources. A pb with JS callbacks stops serving this input: a read, seek or open still waiting for one of its callbacks fails with AVERROR_EXIT, and its callbacks are not called again, so a stalled source cannot block the close.

Direct mapping to avformat_close_input().

Parameters ​

detachPb? ​

boolean = false

Forget a caller-owned pb (custom IOContext) once the reader thread has stopped, so it is not closed with the input. Setting pb = null yourself throws while an async reader is active.

Returns ​

Promise<void>

Promise that resolves when closed

Example ​

typescript
await ctx.closeInput();
// Input closed and context freed

See ​

openInput To open input

closeInputSync() ​

closeInputSync(detachPb?): void

Defined in: src/lib/format-context.ts:662

Close an input format context synchronously. Synchronous version of closeInput.

Closes input file and releases resources. A pb with JS callbacks stops serving this input (see closeInput).

Direct mapping to avformat_close_input().

Parameters ​

detachPb? ​

boolean = false

Forget a caller-owned pb once the reader stopped (see closeInput)

Returns ​

void

Example ​

typescript
ctx.closeInputSync();
// Input closed and context freed

See ​

closeInput For async version

closeOutput() ​

closeOutput(): Promise<void>

Defined in: src/lib/format-context.ts:523

Close output file.

Closes the output file and releases I/O resources.

Direct mapping to avio_closep().

Returns ​

Promise<void>

Promise that resolves when closed

Example ​

typescript
await ctx.closeOutput();
// Output file closed

See ​

openOutput To open output

closeOutputSync() ​

closeOutputSync(): void

Defined in: src/lib/format-context.ts:543

Close output file synchronously. Synchronous version of closeOutput.

Closes the output file and releases I/O resources.

Direct mapping to avio_closep().

Returns ​

void

Example ​

typescript
ctx.closeOutputSync();
// Output file closed

See ​

closeOutput For async version

dumpFormat() ​

dumpFormat(index, url, isOutput): void

Defined in: src/lib/format-context.ts:1256

Print format information.

Dumps human-readable format info to stderr. Useful for debugging.

Direct mapping to av_dump_format().

Parameters ​

index ​

number

Stream index to highlight (-1 for none)

url ​

string

URL to display

isOutput ​

boolean

True for output format, false for input

Returns ​

void

Example ​

typescript
// Dump input format info
ctx.dumpFormat(0, 'input.mp4', false);

// Dump output format info
ctx.dumpFormat(0, 'output.mp4', true);

findBestStream() ​

Call Signature ​

findBestStream(type, wantedStreamNb?, relatedStream?): number

Defined in: src/lib/format-context.ts:1290

Find the best stream of a given type.

Selects the most suitable stream (e.g., default audio/video).

Direct mapping to av_find_best_stream().

Parameters ​
type ​

AVMediaType

Media type to find (AVMEDIA_TYPE_*)

wantedStreamNb? ​

number

Preferred stream index (-1 for auto)

relatedStream? ​

number

Related stream for audio/video sync (-1 for none)

Returns ​

number

Stream index, or negative AVERROR if not found

Example ​
typescript
import { AVMEDIA_TYPE_VIDEO, AVMEDIA_TYPE_AUDIO } from 'node-av/constants';

const videoIndex = ctx.findBestStream(AVMEDIA_TYPE_VIDEO);
if (videoIndex >= 0) {
  console.log(`Best video stream: ${videoIndex}`);
}

const audioIndex = ctx.findBestStream(AVMEDIA_TYPE_AUDIO);
if (audioIndex >= 0) {
  console.log(`Best audio stream: ${audioIndex}`);
}

Call Signature ​

findBestStream(type, wantedStreamNb, relatedStream, wantDecoder, flags?): object

Defined in: src/lib/format-context.ts:1306

Find the best stream and its decoder.

Parameters ​
type ​

AVMediaType

Media type to find

wantedStreamNb ​

number

Preferred stream index

relatedStream ​

number

Related stream index

wantDecoder ​

true

True to also find decoder

flags? ​

number

Reserved flags

Returns ​

object

Object with stream index and decoder

decoder ​

decoder: Codec | null

streamIndex ​

streamIndex: number

findStreamInfo() ​

findStreamInfo(options?): Promise<number>

Defined in: src/lib/format-context.ts:692

Analyze streams to get stream info.

Reads packet headers to fill in stream information. Should be called after openInput for accurate stream data.

Direct mapping to avformat_find_stream_info().

Parameters ​

options? ​

Dictionary[] | null = null

Per-stream options array

Returns ​

Promise<number>

=0 on success, negative AVERROR on error:

  • AVERROR_EOF: End of file reached
  • AVERROR_ENOMEM: Memory allocation failure

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = await ctx.findStreamInfo();
FFmpegError.throwIfError(ret, 'findStreamInfo');
console.log(`Found ${ctx.nbStreams} streams`);

See ​

findStreamInfoSync() ​

findStreamInfoSync(options?): number

Defined in: src/lib/format-context.ts:722

Analyze streams to get stream info synchronously. Synchronous version of findStreamInfo.

Reads packet headers to fill in stream information. Should be called after openInputSync for accurate stream data.

Direct mapping to avformat_find_stream_info().

Parameters ​

options? ​

Dictionary[] | null = null

Per-stream options array

Returns ​

number

=0 on success, negative AVERROR on error:

  • AVERROR_EOF: End of file reached
  • AVERROR_ENOMEM: Memory allocation failure

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = ctx.findStreamInfoSync();
FFmpegError.throwIfError(ret, 'findStreamInfoSync');
console.log(`Found ${ctx.nbStreams} streams`);

See ​

findStreamInfo For async version

flush() ​

flush(): Promise<void>

Defined in: src/lib/format-context.ts:1209

Flush buffered data.

Flushes any buffered packets in muxers.

Direct mapping to avio_flush().

Returns ​

Promise<void>

Example ​

typescript
await ctx.flush();
// Buffered data written to output

flushSync() ​

flushSync(): void

Defined in: src/lib/format-context.ts:1229

Flush buffered data synchronously. Synchronous version of flush.

Flushes any buffered packets in muxers.

Direct mapping to avio_flush().

Returns ​

void

Example ​

typescript
ctx.flushSync();
// Buffered data written to output

See ​

flush For async version

freeContext() ​

freeContext(): void

Defined in: src/lib/format-context.ts:447

Free the format context.

Releases all resources. The context becomes invalid.

Direct mapping to avformat_free_context().

Returns ​

void

Example ​

typescript
ctx.freeContext();
// Context is now invalid

See ​

Symbol.asyncDispose For automatic cleanup

getNative() ​

getNative(): NativeFormatContext

Defined in: src/lib/format-context.ts:1574

Internal

Get the underlying native FormatContext object.

Returns ​

NativeFormatContext

The native FormatContext binding object

Implementation of ​

NativeWrapper.getNative

getOption() ​

Get an option value from this object.

Uses the AVOption API to retrieve options.

Direct mapping to av_opt_get* functions.

Param ​

name

Option name

Param ​

type

Option type (defaults to AV_OPT_TYPE_STRING)

Param ​

searchFlags

Search flags (default: AV_OPT_SEARCH_CHILDREN)

Example ​

typescript
import { AV_OPT_TYPE_STRING, AV_OPT_TYPE_RATIONAL, AV_OPT_TYPE_PIXEL_FMT, AV_OPT_TYPE_INT64 } from 'node-av/constants';

// String options (default)
const preset = obj.getOption('preset');
const codec = obj.getOption('codec', AV_OPT_TYPE_STRING);

// Typed options
const framerate = obj.getOption('framerate', AV_OPT_TYPE_RATIONAL); // Returns {num, den}
const pixFmt = obj.getOption('pix_fmt', AV_OPT_TYPE_PIXEL_FMT); // Returns AVPixelFormat
const bitrate = obj.getOption('bitrate', AV_OPT_TYPE_INT64); // Returns bigint

Call Signature ​

getOption(name, type?, searchFlags?): string | null

Defined in: src/lib/option.ts:1288

Parameters ​
name ​

string

type? ​

AVOptionTypeString

searchFlags? ​

AVOptionSearchFlags

Returns ​

string | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): string | null

Defined in: src/lib/option.ts:1289

Parameters ​
name ​

string

type ​

AVOptionTypeColor

searchFlags? ​

AVOptionSearchFlags

Returns ​

string | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1292

Parameters ​
name ​

string

type ​

AVOptionTypeInt

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): bigint | null

Defined in: src/lib/option.ts:1293

Parameters ​
name ​

string

type ​

AVOptionTypeInt64

searchFlags? ​

AVOptionSearchFlags

Returns ​

bigint | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1294

Parameters ​
name ​

string

type ​

AVOptionTypeUint

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): bigint | null

Defined in: src/lib/option.ts:1295

Parameters ​
name ​

string

type ​

AVOptionTypeUint64

searchFlags? ​

AVOptionSearchFlags

Returns ​

bigint | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1296

Parameters ​
name ​

string

type ​

AVOptionTypeFlags

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): boolean | null

Defined in: src/lib/option.ts:1297

Parameters ​
name ​

string

type ​

AVOptionTypeBool

searchFlags? ​

AVOptionSearchFlags

Returns ​

boolean | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1298

Parameters ​
name ​

string

type ​

AVOptionTypeDuration

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1299

Parameters ​
name ​

string

type ​

AVOptionTypeConst

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1302

Parameters ​
name ​

string

type ​

AVOptionTypeDouble

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): number | null

Defined in: src/lib/option.ts:1303

Parameters ​
name ​

string

type ​

AVOptionTypeFloat

searchFlags? ​

AVOptionSearchFlags

Returns ​

number | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): IRational | null

Defined in: src/lib/option.ts:1306

Parameters ​
name ​

string

type ​

AVOptionTypeRational

searchFlags? ​

AVOptionSearchFlags

Returns ​

IRational | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): IRational | null

Defined in: src/lib/option.ts:1307

Parameters ​
name ​

string

type ​

AVOptionTypeVideoRate

searchFlags? ​

AVOptionSearchFlags

Returns ​

IRational | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): AVPixelFormat | null

Defined in: src/lib/option.ts:1308

Parameters ​
name ​

string

type ​

AVOptionTypePixelFmt

searchFlags? ​

AVOptionSearchFlags

Returns ​

AVPixelFormat | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): AVSampleFormat | null

Defined in: src/lib/option.ts:1309

Parameters ​
name ​

string

type ​

AVOptionTypeSampleFmt

searchFlags? ​

AVOptionSearchFlags

Returns ​

AVSampleFormat | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): IDimension | null

Defined in: src/lib/option.ts:1310

Parameters ​
name ​

string

type ​

AVOptionTypeImageSize

searchFlags? ​

AVOptionSearchFlags

Returns ​

IDimension | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): ChannelLayout | null

Defined in: src/lib/option.ts:1311

Parameters ​
name ​

string

type ​

AVOptionTypeChLayout

searchFlags? ​

AVOptionSearchFlags

Returns ​

ChannelLayout | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): Dictionary | null

Defined in: src/lib/option.ts:1312

Parameters ​
name ​

string

type ​

AVOptionTypeDict

searchFlags? ​

AVOptionSearchFlags

Returns ​

Dictionary | null

Inherited from ​

OptionMember.getOption

Call Signature ​

getOption(name, type, searchFlags?): string | null

Defined in: src/lib/option.ts:1313

Parameters ​
name ​

string

type ​

AVOptionTypeBinary

searchFlags? ​

AVOptionSearchFlags

Returns ​

string | null

Inherited from ​

OptionMember.getOption

getRTSPStreamInfo() ​

getRTSPStreamInfo(): RTSPStreamInfo[] | null

Defined in: src/lib/format-context.ts:1464

Get RTSP stream information.

Returns information about all RTSP streams including codec details. Only works with RTSP input contexts.

Returns ​

RTSPStreamInfo[] | null

Array of stream information objects with codec details, or null if not RTSP

Example ​

typescript
const ctx = new FormatContext();
await ctx.openInput('rtsp://camera/stream?backchannel=1');

const rtspStreams = ctx.getRTSPStreamInfo();
if (rtspStreams) {
  // Find sendonly stream (backchannel)
  const backchannel = rtspStreams.find(s => s.direction === 'sendonly');
  if (backchannel) {
    console.log(`Transport: ${backchannel.transport}`);
    console.log(`Codec ID: ${backchannel.codecId}`);
    console.log(`MIME Type: ${backchannel.mimeType}`);
    console.log(`Payload Type: ${backchannel.payloadType}`);
    if (backchannel.sampleRate) {
      console.log(`Audio: ${backchannel.sampleRate}Hz, ${backchannel.channels} channels`);
    }
  }
}

hasFlags() ​

hasFlags(...flags): boolean

Defined in: src/lib/format-context.ts:1426

Check if format context has specific flags.

Tests whether all specified flags are set using bitwise AND.

Parameters ​

flags ​

...AVFormatFlag[]

One or more flag values to check

Returns ​

boolean

true if all specified flags are set, false otherwise

Example ​

typescript
import { AVFMT_FLAG_GENPTS } from 'node-av/constants';

if (formatContext.hasFlags(AVFMT_FLAG_GENPTS)) {
  console.log('GENPTS flag is set');
}

See ​

interleavedWriteFrame() ​

interleavedWriteFrame(pkt): Promise<number>

Defined in: src/lib/format-context.ts:1107

Write packet with automatic interleaving.

Writes packet with proper interleaving for muxing. Preferred method for writing packets.

Direct mapping to av_interleaved_write_frame().

Parameters ​

pkt ​

Packet | null

Packet to write (null to flush)

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid packet
  • AVERROR_EIO: I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

// Write with proper interleaving
const ret = await ctx.interleavedWriteFrame(packet);
FFmpegError.throwIfError(ret, 'interleavedWriteFrame');

// Flush buffered packets
await ctx.interleavedWriteFrame(null);

See ​

writeFrame For direct writing

interleavedWriteFrameSync() ​

interleavedWriteFrameSync(pkt): number

Defined in: src/lib/format-context.ts:1140

Write packet with automatic interleaving synchronously. Synchronous version of interleavedWriteFrame.

Writes packet with proper interleaving for muxing. Preferred method for writing packets.

Direct mapping to av_interleaved_write_frame().

Parameters ​

pkt ​

Packet | null

Packet to write (null to flush)

Returns ​

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid parameters
  • AVERROR(EIO): I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

// Write packet
const ret = ctx.interleavedWriteFrameSync(packet);
FFmpegError.throwIfError(ret, 'interleavedWriteFrameSync');

// Flush interleaved packets
ctx.interleavedWriteFrameSync(null);

See ​

interleavedWriteFrame For async version

interrupt() ​

interrupt(): void

Defined in: src/lib/format-context.ts:1486

Interrupt any in-progress blocking I/O operation.

Signals the interrupt callback so a blocking call (e.g. av_read_frame() on a quiet RTSP socket) returns immediately instead of waiting for data. The context is not freed and remains valid - this only aborts the pending operation, so a reader can drain and shut down before closing the input. An input pb with JS callbacks stops serving the input as on close: a call waiting for one of its callbacks fails with AVERROR_EXIT, and its callbacks are not called again.

Returns ​

void

Example ​

typescript
ctx.interrupt(); // unblock a stalled readFrame()

See ​

closeInput To close and free the input

listOptions() ​

listOptions(): OptionInfo[]

Defined in: src/lib/option.ts:1428

List all available options for this object.

Uses the AVOption API to enumerate all options. Useful for discovering available settings and their types.

Direct mapping to av_opt_next() iteration.

Returns ​

OptionInfo[]

Array of option information objects

Example ​

typescript
const options = obj.listOptions();
for (const opt of options) {
  console.log(`${opt.name}: ${opt.help}`);
  console.log(`  Type: ${opt.type}, Default: ${opt.defaultValue}`);
  console.log(`  Range: ${opt.min} - ${opt.max}`);
}

See ​

OptionInfo For option metadata structure

Inherited from ​

OptionMember.listOptions

newStream() ​

newStream(c?): Stream

Defined in: src/lib/format-context.ts:1347

Add a new stream to output context.

Creates a new stream for writing.

Direct mapping to avformat_new_stream().

Parameters ​

c? ​

Codec | null = null

Codec for the stream (optional)

Returns ​

Stream

New stream instance

Example ​

typescript
import { Codec } from 'node-av';
import { AV_CODEC_ID_H264 } from 'node-av/constants';

const codec = Codec.findEncoder(AV_CODEC_ID_H264);
const stream = ctx.newStream(codec);
stream.id = ctx.nbStreams - 1;

See ​

Stream For stream configuration

openInput() ​

openInput(url, fmt?, options?): Promise<number>

Defined in: src/lib/format-context.ts:577

Open input file for reading.

Opens and probes the input file, detecting format automatically unless specified.

Direct mapping to avformat_open_input().

Parameters ​

url ​

string

URL or file path to open

fmt? ​

InputFormat | null = null

Force specific input format (null for auto-detect)

options? ​

Dictionary | null = null

Format-specific options

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_ENOENT: File not found
  • AVERROR_INVALIDDATA: Invalid file format
  • AVERROR_EIO: I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = await ctx.openInput('input.mp4');
FFmpegError.throwIfError(ret, 'openInput');

See ​

openInputSync() ​

openInputSync(url, fmt?, options?): number

Defined in: src/lib/format-context.ts:611

Open an input file or URL synchronously. Synchronous version of openInput.

Opens a media file or stream for reading. The format is auto-detected if not specified.

Direct mapping to avformat_open_input().

Parameters ​

url ​

string

File path or URL to open

fmt? ​

InputFormat | null = null

Force specific format (null for auto-detect)

options? ​

Dictionary | null = null

Format-specific options

Returns ​

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid arguments
  • AVERROR(EIO): I/O error
  • AVERROR(ENOMEM): Memory allocation failure

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = ctx.openInputSync('input.mp4');
FFmpegError.throwIfError(ret, 'openInputSync');

See ​

openInput For async version

openOutput() ​

openOutput(): Promise<number>

Defined in: src/lib/format-context.ts:475

Open output file for writing.

Opens the output file specified in url. Must call allocOutputContext2 first.

Direct mapping to avio_open2().

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_ENOENT: File not found
  • AVERROR_EACCES: Permission denied
  • AVERROR_EIO: I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = await ctx.openOutput();
FFmpegError.throwIfError(ret, 'openOutput');

See ​

openOutputSync() ​

openOutputSync(): number

Defined in: src/lib/format-context.ts:502

Open output file synchronously. Synchronous version of openOutput.

Opens output file for writing. I/O context must be set before calling.

Direct mapping to avio_open2().

Returns ​

number

0 on success, negative AVERROR on error:

  • AVERROR(EIO): I/O error
  • AVERROR(ENOMEM): Memory allocation failure

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = ctx.openOutputSync();
FFmpegError.throwIfError(ret, 'openOutputSync');

See ​

openOutput For async version

readFrame() ​

readFrame(pkt): Promise<number>

Defined in: src/lib/format-context.ts:769

Read next packet from the input.

Reads and returns the next packet in the stream. Packet must be unreferenced after use.

Direct mapping to av_read_frame().

Parameters ​

pkt ​

Packet

Packet to read into

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EOF: End of file
  • AVERROR_EXIT: Aborted by interrupt() or closeInput()

The first call starts the context's own reader thread, which is the only thread touching the input from then on: it blocks in av_read_frame(), retries EAGAIN itself and hands packets over through a bounded queue, so a waiting read never occupies a libuv threadpool thread. seekFrame(), seekFile(), sendRTSPPacket() and findStreamInfo() run on that thread between two reads; the sync variants throw while it is active.

Example ​

typescript
import { FFmpegError } from 'node-av';
import { AVERROR_EOF } from 'node-av';

const packet = new Packet();
packet.alloc();

let ret;
while ((ret = await ctx.readFrame(packet)) >= 0) {
  // Process packet
  console.log(`Stream ${packet.streamIndex}, PTS: ${packet.pts}`);
  packet.unref();
}

if (ret !== AVERROR_EOF) {
  FFmpegError.throwIfError(ret, 'readFrame');
}

See ​

seekFrame To seek before reading

readFrameSync() ​

readFrameSync(pkt): number

Defined in: src/lib/format-context.ts:810

Read next packet from the input synchronously. Synchronous version of readFrame.

Reads and returns the next packet in the stream. Packet must be unreferenced after use.

Direct mapping to av_read_frame().

Parameters ​

pkt ​

Packet

Packet to read into

Returns ​

number

0 on success, negative AVERROR on error:

  • AVERROR_EOF: End of file
  • AVERROR_EAGAIN: Temporarily unavailable

Example ​

typescript
import { FFmpegError } from 'node-av';
import { AVERROR_EOF } from 'node-av';

const packet = new Packet();
packet.alloc();

let ret;
while ((ret = ctx.readFrameSync(packet)) >= 0) {
  // Process packet
  console.log(`Stream ${packet.streamIndex}, PTS: ${packet.pts}`);
  packet.unref();
}

if (ret !== AVERROR_EOF) {
  FFmpegError.throwIfError(ret, 'readFrameSync');
}

See ​

readFrame For async version

seekFile() ​

seekFile(streamIndex, minTs, ts, maxTs, flags?): Promise<number>

Defined in: src/lib/format-context.ts:920

Seek to timestamp with bounds.

More precise seeking with min/max timestamp bounds.

Direct mapping to avformat_seek_file().

Parameters ​

streamIndex ​

number

Stream to seek in (-1 for default)

minTs ​

bigint

Minimum acceptable timestamp

ts ​

bigint

Target timestamp

maxTs ​

bigint

Maximum acceptable timestamp

flags? ​

AVSeekFlag = AVFLAG_NONE

Seek flags

Returns ​

Promise<number>

=0 on success, negative AVERROR on error

Example ​

typescript
import { FFmpegError } from 'node-av';

// Seek to 10s with 0.5s tolerance
const target = 10000n;
const ret = await ctx.seekFile(
  -1,
  target - 500n,
  target,
  target + 500n
);
FFmpegError.throwIfError(ret, 'seekFile');

See ​

seekFileSync() ​

seekFileSync(streamIndex, minTs, ts, maxTs, flags?): number

Defined in: src/lib/format-context.ts:962

Seek to timestamp with bounds synchronously. Synchronous version of seekFile.

More precise seeking with min/max timestamp bounds.

Direct mapping to avformat_seek_file().

Parameters ​

streamIndex ​

number

Stream to seek in (-1 for default)

minTs ​

bigint

Minimum acceptable timestamp

ts ​

bigint

Target timestamp

maxTs ​

bigint

Maximum acceptable timestamp

flags? ​

AVSeekFlag = AVFLAG_NONE

Seek flags

Returns ​

number

=0 on success, negative AVERROR on error

Example ​

typescript
import { FFmpegError } from 'node-av';

// Seek to 10s with 0.5s tolerance
const target = 10000n;
const ret = ctx.seekFileSync(
  -1,
  target - 500n,
  target,
  target + 500n
);
FFmpegError.throwIfError(ret, 'seekFileSync');

See ​

seekFrame() ​

seekFrame(streamIndex, timestamp, flags?): Promise<number>

Defined in: src/lib/format-context.ts:843

Seek to timestamp in stream.

Seeks to the keyframe at or before the given timestamp.

Direct mapping to av_seek_frame().

Parameters ​

streamIndex ​

number

Stream to seek in (-1 for default)

timestamp ​

bigint

Target timestamp in stream time base

flags? ​

AVSeekFlag = AVFLAG_NONE

Seek flags (AVSEEK_FLAG_*)

Returns ​

Promise<number>

=0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid parameters
  • AVERROR_EOF: Seek beyond file

Example ​

typescript
import { FFmpegError } from 'node-av';
import { AVSEEK_FLAG_BACKWARD } from 'node-av/constants';

// Seek to 10 seconds (assuming 1/1000 time base)
const ret = await ctx.seekFrame(videoStreamIndex, 10000n, AVSEEK_FLAG_BACKWARD);
FFmpegError.throwIfError(ret, 'seekFrame');

See ​

seekFile For more precise seeking

seekFrameSync() ​

seekFrameSync(streamIndex, timestamp, flags?): number

Defined in: src/lib/format-context.ts:879

Seek to timestamp in stream synchronously. Synchronous version of seekFrame.

Seeks to closest keyframe at or before timestamp. Timestamp is in stream timebase units.

Direct mapping to av_seek_frame().

Parameters ​

streamIndex ​

number

Stream to seek in (-1 for default)

timestamp ​

bigint

Target timestamp in stream timebase

flags? ​

AVSeekFlag = AVFLAG_NONE

Seek flags (AVSEEK_FLAG_*)

Returns ​

number

=0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid arguments
  • AVERROR(EIO): I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';
import { AVSEEK_FLAG_BACKWARD } from 'node-av/constants';

// Seek to 10 seconds
const timestamp = 10n * 1000000n; // Assuming microsecond timebase
const ret = ctx.seekFrameSync(-1, timestamp, AVSEEK_FLAG_BACKWARD);
FFmpegError.throwIfError(ret, 'seekFrameSync');

See ​

seekFrame For async version

sendRTSPPacket() ​

sendRTSPPacket(streamIndex, rtpData): Promise<number>

Defined in: src/lib/format-context.ts:1524

Send RTP packet to RTSP stream (supports both TCP and UDP)

Automatically handles transport-specific packet formatting:

  • TCP: Sends with interleaved header ($channelId + length + RTP)
  • UDP: Sends raw RTP packet directly to UDP socket

Used for backchannel/talkback audio streaming. Only works with RTSP input contexts.

Parameters ​

streamIndex ​

number

RTSP stream index

rtpData ​

Buffer

Raw RTP packet data (12-byte header + payload)

Returns ​

Promise<number>

Promise resolving to number of bytes written on success, negative AVERROR on failure

Example ​

typescript
// Get backchannel stream info
const streams = ctx.getRTSPStreamInfo();
const backchannel = streams.find(s => s.direction === 'sendonly');

if (backchannel) {
  // Send to camera (works with both TCP and UDP)
  const ret = await ctx.sendRTSPPacket(backchannel.streamIndex, rtpPacket);
  if (ret < 0) {
    throw new Error(`Failed to send: ${ret}`);
  }
}

See ​

sendRTSPPacketSync() ​

sendRTSPPacketSync(streamIndex, rtpData): number

Defined in: src/lib/format-context.ts:1563

Send RTP packet to RTSP stream (supports both TCP and UDP) synchronously. Synchronous version of sendRTSPPacket.

Automatically handles transport-specific packet formatting:

  • TCP: Sends with interleaved header ($channelId + length + RTP)
  • UDP: Sends raw RTP packet directly to UDP socket

Used for backchannel/talkback audio streaming. Only works with RTSP input contexts.

Parameters ​

streamIndex ​

number

RTSP stream index

rtpData ​

Buffer

Raw RTP packet data (12-byte header + payload)

Returns ​

number

Number of bytes written on success, negative AVERROR on failure

Example ​

typescript
// Get backchannel stream info
const streams = ctx.getRTSPStreamInfo();
const backchannel = streams.find(s => s.direction === 'sendonly');

if (backchannel) {
  // Send to camera (works with both TCP and UDP)
  const ret = ctx.sendRTSPPacketSync(backchannel.streamIndex, rtpPacket);
  if (ret < 0) {
    throw new Error(`Failed to send: ${ret}`);
  }
}

See ​

setFlags() ​

setFlags(...flags): void

Defined in: src/lib/format-context.ts:1372

Set format flags.

Sets one or more flags using bitwise OR. Allows setting multiple flags without manually performing bitwise operations.

Parameters ​

flags ​

...AVFormatFlag[]

One or more flag values to set

Returns ​

void

Example ​

typescript
import { AVFMT_FLAG_GENPTS, AVFMT_FLAG_IGNIDX } from 'node-av/constants';

// Set multiple flags at once
formatContext.setFlags(AVFMT_FLAG_GENPTS, AVFMT_FLAG_IGNIDX);

See ​

setOption() ​

Set an option on this object.

Uses the AVOption API to set options. Available options depend on the specific object type.

Direct mapping to av_opt_set* functions.

Param ​

name

Option name

Param ​

value

Option value

Param ​

type

Option type; when omitted, the option's declared type is looked up via av_opt_find and the value converted accordingly

Param ​

searchFlags

Search flags (default: AV_OPT_SEARCH_CHILDREN)

Example ​

typescript
import { FFmpegError } from 'node-av';
import { AV_OPT_TYPE_STRING, AV_OPT_TYPE_INT64, AV_OPT_TYPE_RATIONAL, AV_OPT_TYPE_PIXEL_FMT } from 'node-av/constants';

// Untyped - the option's declared type is inferred
let ret = obj.setOption('preset', 'fast');
FFmpegError.throwIfError(ret, 'set preset');

ret = obj.setOption('codec', 'h264', AV_OPT_TYPE_STRING);
FFmpegError.throwIfError(ret, 'set codec');

// Integer options
ret = obj.setOption('bitrate', 2000000, AV_OPT_TYPE_INT64);
FFmpegError.throwIfError(ret, 'set bitrate');

ret = obj.setOption('threads', 4, AV_OPT_TYPE_INT);
FFmpegError.throwIfError(ret, 'set threads');

// Complex types with proper types
ret = obj.setOption('framerate', {num: 30, den: 1}, AV_OPT_TYPE_RATIONAL);
FFmpegError.throwIfError(ret, 'set framerate');

ret = obj.setOption('pix_fmt', AV_PIX_FMT_YUV420P, AV_OPT_TYPE_PIXEL_FMT);
FFmpegError.throwIfError(ret, 'set pixel format');

Call Signature ​

setOption(name, value): number

Defined in: src/lib/option.ts:1066

Parameters ​
name ​

string

value ​

string | number | bigint | boolean | null | undefined

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1067

Parameters ​
name ​

string

value ​

string

type ​

AVOptionTypeString

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1068

Parameters ​
name ​

string

value ​

string

type ​

AVOptionTypeColor

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1071

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeInt

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1072

Parameters ​
name ​

string

value ​

bigint

type ​

AVOptionTypeInt64

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1073

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeUint

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1074

Parameters ​
name ​

string

value ​

bigint

type ​

AVOptionTypeUint64

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1075

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeFlags

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1076

Parameters ​
name ​

string

value ​

boolean

type ​

AVOptionTypeBool

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1077

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeDuration

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1078

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeConst

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1081

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeDouble

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1082

Parameters ​
name ​

string

value ​

number

type ​

AVOptionTypeFloat

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1085

Parameters ​
name ​

string

value ​

IRational

type ​

AVOptionTypeRational

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1086

Parameters ​
name ​

string

value ​

IRational

type ​

AVOptionTypeVideoRate

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1087

Parameters ​
name ​

string

value ​

AVPixelFormat

type ​

AVOptionTypePixelFmt

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1088

Parameters ​
name ​

string

value ​

AVSampleFormat

type ​

AVOptionTypeSampleFmt

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1089

Parameters ​
name ​

string

value ​

IDimension

type ​

AVOptionTypeImageSize

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1090

Parameters ​
name ​

string

value ​

number | bigint

type ​

AVOptionTypeChLayout

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1091

Parameters ​
name ​

string

value ​

Buffer

type ​

AVOptionTypeBinary

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1092

Parameters ​
name ​

string

value ​

number[]

type ​

AVOptionTypeBinaryIntArray

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

Call Signature ​

setOption(name, value, type, searchFlags?): number

Defined in: src/lib/option.ts:1093

Parameters ​
name ​

string

value ​

Dictionary

type ​

AVOptionTypeDict

searchFlags? ​

AVOptionSearchFlags

Returns ​

number

Inherited from ​

OptionMember.setOption

writeFrame() ​

writeFrame(pkt): Promise<number>

Defined in: src/lib/format-context.ts:1048

Write packet to output.

Writes a packet directly without interleaving. Caller must handle correct interleaving.

Direct mapping to av_write_frame().

Parameters ​

pkt ​

Packet | null

Packet to write (null to flush)

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid packet
  • AVERROR_EIO: I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = await ctx.writeFrame(packet);
FFmpegError.throwIfError(ret, 'writeFrame');

See ​

interleavedWriteFrame For automatic interleaving

writeFrameSync() ​

writeFrameSync(pkt): number

Defined in: src/lib/format-context.ts:1075

Write packet to output synchronously. Synchronous version of writeFrame.

Writes a packet directly without interleaving. Caller must handle correct interleaving.

Direct mapping to av_write_frame().

Parameters ​

pkt ​

Packet | null

Packet to write (null to flush)

Returns ​

number

0 on success, negative AVERROR on error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = ctx.writeFrameSync(packet);
FFmpegError.throwIfError(ret, 'writeFrameSync');

See ​

writeFrame For async version

writeHeader() ​

writeHeader(options?): Promise<number>

Defined in: src/lib/format-context.ts:992

Write file header.

Writes the file header and initializes output. Must be called before writing packets.

Direct mapping to avformat_write_header().

Parameters ​

options? ​

Dictionary | null = null

Muxer-specific options

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid parameters
  • AVERROR_EIO: I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = await ctx.writeHeader();
FFmpegError.throwIfError(ret, 'writeHeader');
// Now ready to write packets

See ​

writeHeaderSync() ​

writeHeaderSync(options?): number

Defined in: src/lib/format-context.ts:1020

Write file header synchronously. Synchronous version of writeHeader.

Writes format header to output file. Must be called before writing packets.

Direct mapping to avformat_write_header().

Parameters ​

options? ​

Dictionary | null = null

Muxer-specific options

Returns ​

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid parameters

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = ctx.writeHeaderSync();
FFmpegError.throwIfError(ret, 'writeHeaderSync');

See ​

writeHeader For async version

writeTrailer() ​

writeTrailer(): Promise<number>

Defined in: src/lib/format-context.ts:1166

Write file trailer.

Finalizes the output file, writing index and metadata. Must be called to properly close output files.

Direct mapping to av_write_trailer().

Returns ​

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EIO: I/O error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = await ctx.writeTrailer();
FFmpegError.throwIfError(ret, 'writeTrailer');
// File is now finalized

See ​

writeHeader Must be called first

writeTrailerSync() ​

writeTrailerSync(): number

Defined in: src/lib/format-context.ts:1192

Write file trailer synchronously. Synchronous version of writeTrailer.

Finalizes the output file, writing index and metadata. Must be called to properly close output files.

Direct mapping to av_write_trailer().

Returns ​

number

0 on success, negative AVERROR on error

Example ​

typescript
import { FFmpegError } from 'node-av';

const ret = ctx.writeTrailerSync();
FFmpegError.throwIfError(ret, 'writeTrailerSync');
// File is now finalized

See ​

writeTrailer For async version