playback.md

Playback

TFFVideoPlayer

VCL control with two modes.

Engine mode

Minimal setup – set FileName only:

Player.FileName := 'clip.mp4';
Player.HardwareDevice := ffhdAuto;  // optional; set before Play
Player.Play;

Internally TFFPlaybackEngine creates its own TFFReader / TFFDecoder in worker threads.

Linked mode

Component graph on the form:

Reader.FileName := 'clip.mp4';
Reader.Open;

VideoDecoder.Reader := Reader;
VideoDecoder.StreamIndex := VideoIdx;
VideoDecoder.HardwareDevice := ffhdD3D11VA;

AudioDecoder.Reader := Reader;
AudioDecoder.StreamIndex := AudioIdx;

Player.VideoDecoder := VideoDecoder;
Player.AudioDecoder := AudioDecoder;
Player.Play;

Play / Pause / Stop / SeekTo control TFFLinkedPlayback. Position, Duration, State come from the linked core.

Hardware decode

TFFHardwareDevice (uFFHardwareDecode):

Value	Description
ffhdNone	Software (default)
ffhdAuto	D3D11VA on Windows, VAAPI on Linux
ffhdD3D11VA, ffhdDXVA2, ffhdCUDA, ffhdQSV, …	Explicit backend

Mode	Where to set
Linked	TFFDecoder.HardwareDevice
Engine	TFFVideoPlayer.HardwareDevice or TFFPlaybackEngine.HardwareDevice

Change HardwareDevice only while psStopped. On HW init failure – software fallback (TrySetup).

HW frames are transferred to system memory via av_hwframe_transfer_data before libswscale.

A/V sync

TFFPlaybackClock:

• with audio – master time from audio PTS (SetAudioTimeMs);
• before the first audio frame – wall clock (avoids startup deadlock);
• WaitUntil / IsLate – delay or drop late video frames.

Windows audio: WaveOut (uFFAudioOutputWin), 8-slot ring buffer, Flush on Stop.

Player events

Event	Purpose
OnStateChange	psStopped / psPlaying / psPaused
OnFrameHook	Intercept TFFFrame before conversion
OnVideoHook	Intercept BGRA buffer
OnAudioHook	Intercept PCM before output

TFFPlayerControl

Composite VCL control: TFFVideoPlayer + trackbar + play/pause/stop. FileName, VideoDecoder, SubtitleDecoder forward to the inner player.

FMX

TFFFMXVideoPlayer – FMX equivalent based on TFFPlaybackEngine / linked mode. Requires FMX dependencies at build time.