https://github.com/RealChuan/Qt-Media
qt多媒体套件，结合ffmpeg和mpv，用于增强视频播放和转码。
https://github.com/RealChuan/Qt-Media
aac argb bgra breakpad crashpad ffmpeg gpu-decoding gpu-encoding libass mpv nv12 nv21 opengl qt rgba subtitle transcoding yuv420p yuv422p yuyv422
Last synced: 11 months ago
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qt多媒体套件，结合ffmpeg和mpv，用于增强视频播放和转码。
- Host: GitHub
- URL: https://github.com/RealChuan/Qt-Media
- Owner: RealChuan
- License: gpl-3.0
- Created: 2021-01-14T13:33:57.000Z (over 5 years ago)
- Default Branch: main
- Last Pushed: 2024-11-12T01:25:22.000Z (over 1 year ago)
- Last Synced: 2024-11-12T02:24:39.418Z (over 1 year ago)
- Topics: aac, argb, bgra, breakpad, crashpad, ffmpeg, gpu-decoding, gpu-encoding, libass, mpv, nv12, nv21, opengl, qt, rgba, subtitle, transcoding, yuv420p, yuv422p, yuyv422
- Language: C++
- Homepage:
- Size: 1.88 MB
- Stars: 30
- Watchers: 3
- Forks: 4
- Open Issues: 2
-
Metadata Files:
- Readme: README.en.md
- License: LICENSE
Awesome Lists containing this project
README
# Qt-Ffmpeg
- [Simplified Chinese](README.md)
- [English](README.en.md)
## Player
### Requires a powerful opengl and vulkan yuv rendering module
1. Opengl's fragment shader currently supports limited image formats;
2. In WidgetRender, use the QImage::Format_RGB32 and QImage::Format_ARGB32_Premultiplied image formats whenever possible. The following reasons:
1. Avoid most rendering directly to most of these formats using QPainter. Rendering is best optimized to the Format_RGB32 and Format_ARGB32_Premultiplied formats, and secondarily for rendering to the Format_RGB16, Format_RGBX8888, Format_RGBA8888_Premultiplied, Format_RGBX64 and Format_RGBA64_Premultiplied formats.
### AVFrame image adjustment
1. according to`AVColorSpace`Perform color space conversion;
2. according to`AVColorTransferCharacteristic`Make adjustments to gamma, PQ, HLG, etc.;
3. according to`AVColorPrimaries`Perform color gamut conversion;
4. according to`AVColorRange`Make color range adjustments;
#### 1. How to modify the shader when rendering with opengl?
1. reference[MPV video_shaders](https://github.com/mpv-player/mpv/blob/master/video/out/gpu/video_shaders.c)；
#### 2. In the case of non-opengl rendering, how to add a filter to achieve image compensation?
```bash
zscale=p=709;
```
### How to achieve image quality enhancement when rendering images with OpenGL?
### Ffmpeg (5.0) decodes subtitles differently than 4.4.3
#### Decode subtitles (ffmpeg-n5.0)
```bash
0,,en,,0000,0000,0000,,Peek-a-boo!
```
you have to use`ass_process_chunk`and set pts and duration, and in[vf_subtitles.c](https://github.com/FFmpeg/FFmpeg/blob/master/libavfilter/vf_subtitles.c#L490)Same as in.
#### The ASS standard format should be (ffmpeg-n4.4.3)
```bash
Dialogue: 0,0:01:06.77,0:01:08.00,en,,0000,0000,0000,,Peek-a-boo!\r\n
```
use`ass_process_data`;
### Issue with subtitle display timing when using subtitle filter
```bash
subtitles=filename='%1':original_size=%2x%3
```
## Transcoder
How to set encoding parameters to get smaller files and better video quality?
1. reference[HandBrake encavcodec](https://github.com/HandBrake/HandBrake/blob/master/libhb/encavcodec.c#L359)
### How to calculate pts from frames obtained by AVAudioFifo?
```C++
// fix me?
frame->pts = transcodeCtx->audioPts / av_q2d(transcodeCtx->decContextInfoPtr->timebase())
/ transcodeCtx->decContextInfoPtr->codecCtx()->sampleRate();
transcodeCtx->audioPts += frame->nb_samples;
```
### [New BING’s video transcoding recommendations](./doc/bing_transcode.md)
## SwsContext is great! Compared to QImage convert to and scale
## QT-BUG
### Dynamically switching Video Render, switching from opengl to widget, still consumes GPU 0-3D, and the usage is twice that of opengl! ! ! QT-BUG?
### QOpenGLWidget memory leaks, moves to zoom in and out the window, the code is as follows
```C++
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
setCentralWidget(new QOpenGLWidget(this));
}
```