public class VideoWriterBuilder

Object
VideoWriterBuilder

A fluent builder describing how a video file should be encoded. It mirrors the style of MediaRecorderBuilder but covers the full set of knobs needed for video: dimensions, frame rate, codec, bitrate and key frame (GOP) interval, plus the audio track parameters. Build a VideoWriter with #build() and then push frames and audio into it.

Example:

VideoWriter w = new VideoWriterBuilder()
        .path(FileSystemStorage.getInstance().getAppHomePath() + "/out.mp4")
        .width(720).height(1280).frameRate(30)
        .videoCodec(VideoIO.CODEC_H264).videoBitRate(4_000_000)
        .hasAudio(true).audioCodec(VideoIO.CODEC_AAC).sampleRate(44100).audioChannels(2)
        .build();

Constructors

public VideoWriterBuilder()

Methods

`public` `VideoWriterBuilder path(String path)`	Sets the output path where the encoded video will be written, as a `com.codename1.io.FileSystemStorage` path.
`public` `VideoWriterBuilder container(String container)`	Sets the container format, e.g. `VideoIO#CONTAINER_MP4` (default) or `VideoIO#CONTAINER_WEBM`.
`public` `VideoWriterBuilder hasVideo(boolean hasVideo)`	Enables or disables the video track.
`public` `VideoWriterBuilder width(int width)`	Sets the frame width in pixels.
`public` `VideoWriterBuilder height(int height)`	Sets the frame height in pixels.
`public` `VideoWriterBuilder frameRate(float frameRate)`	Sets the constant target frame rate in frames per second.
`public` `VideoWriterBuilder videoCodec(String videoCodec)`	Sets the video codec by id, e.g. `VideoIO#CODEC_H264` (default).
`public` `VideoWriterBuilder videoBitRate(int videoBitRate)`	Sets the target video bitrate in bits per second.
`public` `VideoWriterBuilder keyFrameInterval(float seconds)`	Sets the key frame (GOP) interval in seconds.
`public` `VideoWriterBuilder hasAudio(boolean hasAudio)`	Enables or disables the audio track.
`public` `VideoWriterBuilder audioCodec(String audioCodec)`	Sets the audio codec by id, e.g. `VideoIO#CODEC_AAC` (default).
`public` `VideoWriterBuilder audioBitRate(int audioBitRate)`	Sets the target audio bitrate in bits per second.
`public` `VideoWriterBuilder sampleRate(int sampleRate)`	Sets the audio sample rate in Hz.
`public` `VideoWriterBuilder audioChannels(int audioChannels)`	Sets the number of audio channels.
`public` `VideoWriter build() throws IOException`	Builds the `VideoWriter` with the current settings.
`public` `String getPath()`	The configured output path.
`public` `String getContainer()`	The configured container format.
`public boolean isHasVideo()`	True if the video track is enabled.
`public int getWidth()`	The configured frame width.
`public int getHeight()`	The configured frame height.
`public float getFrameRate()`	The configured frame rate.
`public` `String getVideoCodec()`	The configured video codec id.
`public int getVideoBitRate()`	The configured video bitrate, or -1 to let the implementation choose.
`public float getKeyFrameInterval()`	The configured key frame interval in seconds.
`public boolean isHasAudio()`	True if the audio track is enabled.
`public` `String getAudioCodec()`	The configured audio codec id.
`public int getAudioBitRate()`	The configured audio bitrate.
`public int getSampleRate()`	The configured audio sample rate.
`public int getAudioChannels()`	The configured audio channel count.

Inherited methods

From Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait, clone

Constructor details

VideoWriterBuilder

public VideoWriterBuilder()

Method details

path

public VideoWriterBuilder path(String path)

Sets the output path where the encoded video will be written, as a com.codename1.io.FileSystemStorage path. Required.

Parameters

path String: the output FileSystemStorage path

Returns

Self for chaining.

container

public VideoWriterBuilder container(String container)

Sets the container format, e.g. VideoIO#CONTAINER_MP4 (default) or VideoIO#CONTAINER_WEBM.

Returns

Self for chaining.

hasVideo

public VideoWriterBuilder hasVideo(boolean hasVideo)

Enables or disables the video track. Defaults to true.

Audio-only output (hasVideo(false)) is not currently implemented by the platform backends, so build() rejects it rather than silently producing a file with an empty or unexpected video track.

Returns

Self for chaining.

width

public VideoWriterBuilder width(int width)

Sets the frame width in pixels. Default 1280.

Returns

Self for chaining.

height

public VideoWriterBuilder height(int height)

Sets the frame height in pixels. Default 720.

Returns

Self for chaining.

frameRate

public VideoWriterBuilder frameRate(float frameRate)

Sets the constant target frame rate in frames per second. Default 30. Frames are timestamped by the application when calling VideoWriter#writeFrame, this value is the nominal rate written into the file metadata and used by encoders that need it.

Returns

Self for chaining.

videoCodec

public VideoWriterBuilder videoCodec(String videoCodec)

Sets the video codec by id, e.g. VideoIO#CODEC_H264 (default). Use VideoIO#getAvailableEncoders() to discover what the platform supports.

Returns

Self for chaining.

videoBitRate

public VideoWriterBuilder videoBitRate(int videoBitRate)

Sets the target video bitrate in bits per second. When left at the default (-1) the implementation picks a reasonable value derived from the resolution and frame rate.

Returns

Self for chaining.

keyFrameInterval

public VideoWriterBuilder keyFrameInterval(float seconds)

Sets the key frame (GOP) interval in seconds. A smaller value produces files that seek more accurately at the cost of size. Default 2 seconds.

Returns

Self for chaining.

hasAudio

public VideoWriterBuilder hasAudio(boolean hasAudio)

Enables or disables the audio track. Defaults to false. When enabled, push PCM samples with VideoWriter#writeAudio.

Returns

Self for chaining.

audioCodec

public VideoWriterBuilder audioCodec(String audioCodec)

Sets the audio codec by id, e.g. VideoIO#CODEC_AAC (default).

Returns

Self for chaining.

audioBitRate

public VideoWriterBuilder audioBitRate(int audioBitRate)

Sets the target audio bitrate in bits per second. Default 128000.

Returns

Self for chaining.

sampleRate

public VideoWriterBuilder sampleRate(int sampleRate)

Sets the audio sample rate in Hz. Default 44100.

Returns

Self for chaining.

audioChannels

public VideoWriterBuilder audioChannels(int audioChannels)

Sets the number of audio channels. Default 2.

Returns

Self for chaining.

build

public VideoWriter build()
throws IOException

Builds the VideoWriter with the current settings.

Throws

IOException: if the writer could not be created
IllegalStateException: if #path(String) was not set, video encoding is not supported on this platform, or audio-only output (#hasVideo(boolean) set to false) was requested

getPath

public String getPath()

The configured output path.

getContainer

public String getContainer()

The configured container format.

isHasVideo

public boolean isHasVideo()

True if the video track is enabled.

getWidth

public int getWidth()

The configured frame width.

getHeight

public int getHeight()

The configured frame height.

getFrameRate

public float getFrameRate()

The configured frame rate.

getVideoCodec

public String getVideoCodec()

The configured video codec id.

getVideoBitRate

public int getVideoBitRate()

The configured video bitrate, or -1 to let the implementation choose.

getKeyFrameInterval

public float getKeyFrameInterval()

The configured key frame interval in seconds.

isHasAudio

public boolean isHasAudio()

True if the audio track is enabled.

getAudioCodec

public String getAudioCodec()

The configured audio codec id.

getAudioBitRate

public int getAudioBitRate()

The configured audio bitrate.

getSampleRate

public int getSampleRate()

The configured audio sample rate.

getAudioChannels

public int getAudioChannels()

The configured audio channel count.