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node-av / lib / FilterContext

Class: FilterContext

Defined in: src/lib/filter-context.ts:48

Filter instance in a filter graph.

Represents an instantiated filter within a filter graph. Each context contains a specific filter configuration with its parameters, connections to other filters, and input/output pads. Supports both software and hardware filtering operations. Essential for building complex filter chains for audio/video processing.

Direct mapping to FFmpeg's AVFilterContext.

Example

typescript
import { FilterContext, FilterGraph, Filter, FFmpegError } from 'node-av';

// Create filter context in a graph
const graph = new FilterGraph();
const filter = Filter.getByName('scale');
const context = graph.createFilter(filter, 'scaler');

// Initialize with parameters
const ret = context.initStr('640:480');
FFmpegError.throwIfError(ret, 'initStr');

// Link filters together
const ret2 = source.link(0, context, 0);
FFmpegError.throwIfError(ret2, 'link');

// For buffer source/sink
const ret3 = await bufferSrc.buffersrcAddFrame(frame);
FFmpegError.throwIfError(ret3, 'buffersrcAddFrame');

See

Extends

Implements

Constructors

Constructor

new FilterContext(native): FilterContext

Defined in: src/lib/filter-context.ts:54

Internal

Parameters

native

NativeFilterContext

The native filter context instance

Returns

FilterContext

Overrides

OptionMember<NativeFilterContext>.constructor

Properties

native

protected native: NativeFilterContext

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

Inherited from

OptionMember.native

Accessors

extraHWFrames

Get Signature

get extraHWFrames(): number

Defined in: src/lib/filter-context.ts:152

Number of extra hardware frames to allocate.

Specifies additional hardware frame buffers for filters that need them. Useful for deinterlacing or other filters requiring frame buffering.

Direct mapping to AVFilterContext->extra_hw_frames.

Returns

number

Set Signature

set extraHWFrames(value): void

Defined in: src/lib/filter-context.ts:156

Parameters
value

number

Returns

void


filter

Get Signature

get filter(): Filter | null

Defined in: src/lib/filter-context.ts:81

Filter descriptor.

Reference to the filter type this context instantiates.

Direct mapping to AVFilterContext->filter.

Returns

Filter | null


graph

Get Signature

get graph(): NativeFilterGraph | null

Defined in: src/lib/filter-context.ts:93

Parent filter graph.

Reference to the graph containing this filter context.

Direct mapping to AVFilterContext->graph.

Returns

NativeFilterGraph | null


hwDeviceCtx

Get Signature

get hwDeviceCtx(): HardwareDeviceContext | null

Defined in: src/lib/filter-context.ts:127

Hardware device context.

Hardware acceleration context for GPU-based filtering. Set to enable hardware-accelerated filter operations.

Direct mapping to AVFilterContext->hw_device_ctx.

Returns

HardwareDeviceContext | null

Set Signature

set hwDeviceCtx(value): void

Defined in: src/lib/filter-context.ts:140

Parameters
value

HardwareDeviceContext | null

Returns

void


name

Get Signature

get name(): string | null

Defined in: src/lib/filter-context.ts:66

Filter instance name.

User-assigned name for this filter instance in the graph. Used for identification and debugging.

Direct mapping to AVFilterContext->name.

Returns

string | null

Set Signature

set name(value): void

Defined in: src/lib/filter-context.ts:70

Parameters
value

string | null

Returns

void


nbInputs

Get Signature

get nbInputs(): number

Defined in: src/lib/filter-context.ts:104

Number of input pads.

Total number of input connections this filter can accept.

Direct mapping to AVFilterContext->nb_inputs.

Returns

number


nbOutputs

Get Signature

get nbOutputs(): number

Defined in: src/lib/filter-context.ts:115

Number of output pads.

Total number of output connections this filter can provide.

Direct mapping to AVFilterContext->nb_outputs.

Returns

number

Methods

[dispose]()

[dispose](): void

Defined in: src/lib/filter-context.ts:831

Dispose of the filter context.

Implements the Disposable interface for automatic cleanup. Equivalent to calling free().

Returns

void

Example

typescript
{
  using context = graph.createFilter(filter, 'test');
  context.initStr('640:480');
  // Use context...
} // Automatically freed when leaving scope

Implementation of

Disposable.[dispose]


buffersinkGetChannelLayout()

buffersinkGetChannelLayout(): ChannelLayout

Defined in: src/lib/filter-context.ts:701

Get channel layout from buffer sink.

Returns the channel layout of audio from a buffer sink filter. Only valid for audio buffer sink filters.

Direct mapping to av_buffersink_get_channel_layout().

Returns

ChannelLayout

Channel layout configuration

Example

typescript
const layout = bufferSink.buffersinkGetChannelLayout();
console.log(`Channels: ${layout.nbChannels}`);

buffersinkGetColorRange()

buffersinkGetColorRange(): AVColorRange

Defined in: src/lib/filter-context.ts:741

Get color range from buffer sink.

Returns the color range of video from a buffer sink filter. Only valid for video buffer sink filters.

Direct mapping to av_buffersink_get_color_range().

Returns

AVColorRange

Color range

Example

typescript
const colorRange = bufferSink.buffersinkGetColorRange();
console.log(`Color range: ${colorRange}`);

buffersinkGetColorspace()

buffersinkGetColorspace(): AVColorSpace

Defined in: src/lib/filter-context.ts:721

Get color space from buffer sink.

Returns the color space of video from a buffer sink filter. Only valid for video buffer sink filters.

Direct mapping to av_buffersink_get_colorspace().

Returns

AVColorSpace

Color space

Example

typescript
const colorSpace = bufferSink.buffersinkGetColorspace();
console.log(`Color space: ${colorSpace}`);

buffersinkGetFormat()

buffersinkGetFormat(): AVPixelFormat | AVSampleFormat

Defined in: src/lib/filter-context.ts:579

Get pixel/sample format from buffer sink.

Returns the format of frames from a buffer sink filter. Only valid for buffer sink filters.

Direct mapping to av_buffersink_get_format().

Returns

AVPixelFormat | AVSampleFormat

Pixel format for video, sample format for audio

Example

typescript
import { AV_PIX_FMT_YUV420P } from 'node-av/constants';

const format = bufferSink.buffersinkGetFormat();
if (format === AV_PIX_FMT_YUV420P) {
  console.log('Output is YUV420P');
}

buffersinkGetFrame()

buffersinkGetFrame(frame): Promise<number>

Defined in: src/lib/filter-context.ts:490

Get a frame from a buffer sink filter.

Retrieves a filtered frame from the filter graph through a buffer sink. Only valid for buffer sink filters.

Direct mapping to av_buffersink_get_frame().

Parameters

frame

Frame

Frame to receive filtered data

Returns

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EAGAIN: No frame available yet
  • AVERROR_EOF: No more frames will be produced
  • AVERROR_EINVAL: Not a buffer sink filter

Example

typescript
import { FFmpegError, Frame } from 'node-av';
import { AVERROR_EAGAIN, AVERROR_EOF } from 'node-av/constants';

const frame = new Frame();
frame.alloc();

const ret = await bufferSink.buffersinkGetFrame(frame);
if (ret === AVERROR_EAGAIN) {
  // No frame available yet
} else if (ret === AVERROR_EOF) {
  // End of stream
} else {
  FFmpegError.throwIfError(ret, 'buffersinkGetFrame');
  // Process filtered frame
}

See

buffersrcAddFrame To send frames for filtering


buffersinkGetFrameRate()

buffersinkGetFrameRate(): Rational

Defined in: src/lib/filter-context.ts:660

Get frame rate from buffer sink.

Returns the frame rate of video from a buffer sink filter. Only valid for video buffer sink filters.

Direct mapping to av_buffersink_get_frame_rate().

Returns

Rational

Frame rate as Rational

Example

typescript
const frameRate = bufferSink.buffersinkGetFrameRate();
console.log(`Frame rate: ${frameRate.num}/${frameRate.den} fps`);

buffersinkGetFrameSync()

buffersinkGetFrameSync(frame): number

Defined in: src/lib/filter-context.ts:534

Get frame from buffer sink filter synchronously. Synchronous version of buffersinkGetFrame.

Retrieves a filtered frame from a buffer sink filter. Only valid for buffer sink filters (buffersink, abuffersink).

Direct mapping to av_buffersink_get_frame().

Parameters

frame

Frame

Frame to receive filtered data

Returns

number

0 on success, negative AVERROR on error:

  • AVERROR_EAGAIN: Need more input
  • AVERROR_EOF: No more frames available
  • AVERROR_EINVAL: Invalid parameters

Example

typescript
import { Frame, FFmpegError } from 'node-av';
import { AVERROR_EAGAIN, AVERROR_EOF } from 'node-av/constants';

// Get filtered frame
const filtered = new Frame();
const ret = bufferSink.buffersinkGetFrameSync(filtered);

if (ret === 0) {
  // Process filtered frame
  console.log(`Got filtered frame with ${filtered.nbSamples} samples`);
  filtered.unref();
} else if (ret === AVERROR_EAGAIN) {
  // Need more input frames
} else if (ret === AVERROR_EOF) {
  // No more frames
} else {
  FFmpegError.throwIfError(ret, 'buffersinkGetFrameSync');
}

See

buffersinkGetFrame For async version


buffersinkGetHeight()

buffersinkGetHeight(): number

Defined in: src/lib/filter-context.ts:619

Get frame height from buffer sink.

Returns the height of video frames from a buffer sink filter. Only valid for video buffer sink filters.

Direct mapping to av_buffersink_get_h().

Returns

number

Frame height in pixels

Example

typescript
const height = bufferSink.buffersinkGetHeight();
console.log(`Output height: ${height}px`);

buffersinkGetSampleAspectRatio()

buffersinkGetSampleAspectRatio(): Rational

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

Get sample aspect ratio from buffer sink.

Returns the pixel aspect ratio of video frames from a buffer sink filter. Only valid for video buffer sink filters.

Direct mapping to av_buffersink_get_sample_aspect_ratio().

Returns

Rational

Sample aspect ratio as Rational

Example

typescript
const sar = bufferSink.buffersinkGetSampleAspectRatio();
console.log(`SAR: ${sar.num}:${sar.den}`);

buffersinkGetSampleRate()

buffersinkGetSampleRate(): number

Defined in: src/lib/filter-context.ts:681

Get sample rate from buffer sink.

Returns the sample rate of audio from a buffer sink filter. Only valid for audio buffer sink filters.

Direct mapping to av_buffersink_get_sample_rate().

Returns

number

Sample rate in Hz

Example

typescript
const sampleRate = bufferSink.buffersinkGetSampleRate();
console.log(`Sample rate: ${sampleRate} Hz`);

buffersinkGetTimeBase()

buffersinkGetTimeBase(): Rational

Defined in: src/lib/filter-context.ts:554

Get time base from buffer sink.

Returns the time base of frames from a buffer sink filter. Only valid for buffer sink filters.

Direct mapping to av_buffersink_get_time_base().

Returns

Rational

Time base as Rational

Example

typescript
const timeBase = bufferSink.buffersinkGetTimeBase();
console.log(`Time base: ${timeBase.num}/${timeBase.den}`);

buffersinkGetWidth()

buffersinkGetWidth(): number

Defined in: src/lib/filter-context.ts:599

Get frame width from buffer sink.

Returns the width of video frames from a buffer sink filter. Only valid for video buffer sink filters.

Direct mapping to av_buffersink_get_w().

Returns

number

Frame width in pixels

Example

typescript
const width = bufferSink.buffersinkGetWidth();
console.log(`Output width: ${width}px`);

buffersrcAddFrame()

buffersrcAddFrame(frame, flags?): Promise<number>

Defined in: src/lib/filter-context.ts:318

Add a frame to a buffer source filter.

Sends a frame into the filter graph through a buffer source. Only valid for buffer source filters. Send null to signal EOF.

Direct mapping to av_buffersrc_add_frame_flags().

Parameters

frame

Frame | null

Frame to send, or null for EOF

flags?

AVBufferSrcFlag

Optional buffersrc flags (defaults to AV_BUFFERSRC_FLAG_NONE = 0)

Returns

Promise<number>

0 on success, negative AVERROR on error:

  • AVERROR_EAGAIN: Filter needs more output consumption
  • AVERROR_EOF: Filter has been closed
  • AVERROR_EINVAL: Not a buffer source filter
  • AVERROR_ENOMEM: Memory allocation failure

Example

typescript
import { FFmpegError } from 'node-av';
import { AVERROR_EAGAIN, AV_BUFFERSRC_FLAG_PUSH } from 'node-av/constants';

// Send frame to filter graph with PUSH flag (immediate processing)
const ret = await bufferSrc.buffersrcAddFrame(frame, AV_BUFFERSRC_FLAG_PUSH);
if (ret === AVERROR_EAGAIN) {
  // Need to consume output first
} else {
  FFmpegError.throwIfError(ret, 'buffersrcAddFrame');
}

// Signal EOF
await bufferSrc.buffersrcAddFrame(null);

See

buffersinkGetFrame To retrieve filtered frames


buffersrcAddFrameSync()

buffersrcAddFrameSync(frame, flags?): number

Defined in: src/lib/filter-context.ts:362

Add frame to buffer source filter synchronously. Synchronous version of buffersrcAddFrame.

Sends a frame to a buffer source filter for processing. Only valid for buffer source filters (buffer, abuffer).

Direct mapping to av_buffersrc_add_frame_flags().

Parameters

frame

Frame | null

Frame to send (null to mark EOF)

flags?

AVBufferSrcFlag

Optional buffersrc flags (defaults to AV_BUFFERSRC_FLAG_NONE = 0)

Returns

number

0 on success, negative AVERROR on error:

  • AVERROR_EAGAIN: Need to retrieve output first
  • AVERROR_EOF: Graph has finished processing
  • AVERROR_EINVAL: Invalid parameters
  • AVERROR(ENOMEM): Memory allocation failure

Example

typescript
import { FFmpegError } from 'node-av';
import { AVERROR_EAGAIN, AV_BUFFERSRC_FLAG_PUSH } from 'node-av/constants';

// Send frame to filter with PUSH flag (immediate processing)
const ret = bufferSrc.buffersrcAddFrameSync(frame, AV_BUFFERSRC_FLAG_PUSH);
if (ret === AVERROR_EAGAIN) {
  // Need to get output frames first
  const filtered = new Frame();
  bufferSink.buffersinkGetFrameSync(filtered);
} else {
  FFmpegError.throwIfError(ret, 'buffersrcAddFrameSync');
}

// Mark end of stream
bufferSrc.buffersrcAddFrameSync(null);

See

buffersrcAddFrame For async version


buffersrcParametersSet()

buffersrcParametersSet(params): number

Defined in: src/lib/filter-context.ts:433

Set parameters for a buffer source filter.

Configures the format and properties of frames that will be sent to the buffer source. Must be called before sending frames.

Direct mapping to av_buffersrc_parameters_set().

Parameters

params

Source parameters

alphaMode?

number

Alpha channel mode

channelLayout?

bigint

Audio channel layout

colorRange?

AVColorRange

Color range for video

colorSpace?

AVColorSpace

Color space for video

format?

AVPixelFormat | AVSampleFormat

Pixel or sample format

frameRate?

IRational

Video frame rate

height?

number

Video frame height

hwFramesCtx?

HardwareFramesContext | null

Hardware frames context

sampleAspectRatio?

IRational

Pixel aspect ratio

sampleRate?

number

Audio sample rate

timeBase?

IRational

Time base for timestamps

width?

number

Video frame width

Returns

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid parameters
  • AVERROR_ENOMEM: Memory allocation failure

Example

typescript
import { FFmpegError, Rational } from 'node-av';
import { AV_PIX_FMT_YUV420P } from 'node-av/constants';

// Configure video buffer source
const ret = bufferSrc.buffersrcParametersSet({
  width: 1920,
  height: 1080,
  format: AV_PIX_FMT_YUV420P,
  timeBase: { num: 1, den: 25 },
  frameRate: { num: 25, den: 1 }
});
FFmpegError.throwIfError(ret, 'buffersrcParametersSet');

@example
```typescript
import { FFmpegError } from 'node-av';
import { AV_SAMPLE_FMT_FLTP } from 'node-av/constants';

// Configure audio buffer source
const ret = bufferSrc.buffersrcParametersSet({
  format: AV_SAMPLE_FMT_FLTP,
  sampleRate: 44100,
  channelLayout: AV_CHANNEL_LAYOUT_STEREO
});
FFmpegError.throwIfError(ret, 'buffersrcParametersSet');

free()

free(): void

Defined in: src/lib/filter-context.ts:761

Free the filter context.

Releases all resources associated with the filter context. The context becomes invalid after calling this.

Direct mapping to avfilter_free().

Returns

void

Example

typescript
context.free();
// Context is now invalid

See

Symbol.dispose For automatic cleanup


getNative()

getNative(): NativeFilterContext

Defined in: src/lib/filter-context.ts:812

Internal

Get the underlying native FilterContext object.

Returns

NativeFilterContext

The native FilterContext 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


init()

init(options?): number

Defined in: src/lib/filter-context.ts:185

Initialize filter with dictionary options.

Configures the filter with key-value option pairs. Must be called after creation and before processing.

Direct mapping to avfilter_init_dict().

Parameters

options?

NativeDictionary | null

Dictionary of filter options

Returns

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid parameters
  • AVERROR_ENOMEM: Memory allocation failure

Example

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

const options = { width: '1920', height: '1080' };
const ret = context.init(options);
FFmpegError.throwIfError(ret, 'init');

See

initStr For string-based initialization


initStr()

initStr(args?): number

Defined in: src/lib/filter-context.ts:218

Initialize filter with string arguments.

Configures the filter using a string representation of parameters. Format depends on the specific filter.

Direct mapping to avfilter_init_str().

Parameters

args?

string | null

Filter arguments string

Returns

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid arguments
  • AVERROR_ENOMEM: Memory allocation failure

Example

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

// Scale filter with width:height
const ret = scaleContext.initStr('1920:1080');
FFmpegError.throwIfError(ret, 'initStr');

// Crop filter with width:height:x:y
const ret2 = cropContext.initStr('640:480:100:50');
FFmpegError.throwIfError(ret2, 'initStr');

See

init For dictionary-based initialization


isSink()

isSink(): boolean

Defined in: src/lib/filter-context.ts:801

Check if filter is a sink.

Sink filters consume frames without output.

Returns

boolean

True if filter has no outputs

Example

typescript
if (context.isSink()) {
  console.log('This is a sink filter');
}

See

isSource To check for source filters


isSource()

isSource(): boolean

Defined in: src/lib/filter-context.ts:781

Check if filter is a source.

Source filters generate frames without input.

Returns

boolean

True if filter has no inputs

Example

typescript
if (context.isSource()) {
  console.log('This is a source filter');
}

See

isSink To check for sink filters


link(srcPad, dst, dstPad): number

Defined in: src/lib/filter-context.ts:255

Link this filter's output to another filter's input.

Creates a connection between two filters in the graph. Data flows from this filter's output pad to the destination's input pad.

Direct mapping to avfilter_link().

Parameters

srcPad

number

Output pad index of this filter

dst

FilterContext

Destination filter context

dstPad

number

Input pad index of destination filter

Returns

number

0 on success, negative AVERROR on error:

  • AVERROR_EINVAL: Invalid pad indices or incompatible formats
  • AVERROR_ENOMEM: Memory allocation failure

Example

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

// Link source output 0 to scale input 0
const ret = source.link(0, scale, 0);
FFmpegError.throwIfError(ret, 'link');

// Link scale output 0 to sink input 0
const ret2 = scale.link(0, sink, 0);
FFmpegError.throwIfError(ret2, 'link');

See

unlink To disconnect filters


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


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


unlink(pad): void

Defined in: src/lib/filter-context.ts:277

Unlink a filter pad.

Disconnects a pad from its linked filter. Used to reconfigure filter connections.

Direct mapping to avfilter_link_free().

Parameters

pad

number

Pad index to unlink

Returns

void

Example

typescript
// Disconnect output pad 0
context.unlink(0);

See

link To connect filters