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我使用以下代碼來一系列的幀編碼爲與FFV1編碼的MKV或avi文件：libavcodec的：與FFV1編解碼器編碼文件ffprobe報告「read_quant_table錯誤」
HRESULT Session::createContext(LPCSTR filename, UINT width, UINT height, UINT fps_num, UINT fps_den) {
LOG("Exporting to file: ", filename);
AVCodecID codecId = AV_CODEC_ID_FFV1;
this->pixelFormat = AV_PIX_FMT_YUV420P;
this->codec = avcodec_find_encoder(codecId);
RET_IF_NULL(this->codec, "Could not create codec", E_FAIL);
this->oformat = av_guess_format(NULL, filename, NULL);
RET_IF_NULL(this->oformat, "Could not create format", E_FAIL);
this->oformat->video_codec = codecId;
this->width = width;
this->height = height;
this->codecContext = avcodec_alloc_context3(this->codec);
RET_IF_NULL(this->codecContext, "Could not allocate context for the codec", E_FAIL);
this->codecContext->codec = this->codec;
this->codecContext->codec_id = codecId;
this->codecContext->pix_fmt = pixelFormat;
this->codecContext->width = this->width;
this->codecContext->height = this->height;
this->codecContext->time_base.num = fps_den;
this->codecContext->time_base.den = fps_num;
this->codecContext->gop_size = 1;
RET_IF_FAILED_AV(avformat_alloc_output_context2(&fmtContext, this->oformat, NULL, NULL), "Could not allocate format context", E_FAIL);
RET_IF_NULL(this->fmtContext, "Could not allocate format context", E_FAIL);
this->fmtContext->oformat = this->oformat;
this->fmtContext->video_codec_id = codecId;
this->stream = avformat_new_stream(this->fmtContext, this->codec);
RET_IF_NULL(this->stream, "Could not create new stream", E_FAIL);
this->stream->time_base = this->codecContext->time_base;
RET_IF_FAILED_AV(avcodec_parameters_from_context(this->stream->codecpar, this->codecContext), "Could not convert AVCodecContext to AVParameters", E_FAIL);
if (this->fmtContext->oformat->flags & AVFMT_GLOBALHEADER)
{
this->codecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
av_opt_set_int(this->codecContext->priv_data, "coder", 0, 0);
av_opt_set_int(this->codecContext->priv_data, "context", 1, 0);
av_opt_set_int(this->codecContext->priv_data, "slicecrc", 1, 0);
//av_opt_set_int(this->codecContext->priv_data, "slicecrc", 1, 0);
//av_opt_set_int(this->codecContext->priv_data, "pix_fmt", pixelFormat, 0);
RET_IF_FAILED_AV(avcodec_open2(this->codecContext, this->codec, NULL), "Could not open codec", E_FAIL);
RET_IF_FAILED_AV(avio_open(&this->fmtContext->pb, filename, AVIO_FLAG_WRITE), "Could not open output file", E_FAIL);
RET_IF_NULL(this->fmtContext->pb, "Could not open output file", E_FAIL);
RET_IF_FAILED_AV(avformat_write_header(this->fmtContext, NULL), "Could not write header", E_FAIL);
frame = av_frame_alloc();
RET_IF_NULL(frame, "Could not allocate frame", E_FAIL);
frame->format = this->codecContext->pix_fmt;
frame->width = width;
frame->height = height;
return S_OK;
}
HRESULT Session::writeFrame(IMFSample * pSample) {
IMFMediaBuffer *mediaBuffer = NULL;
BYTE *pDataNV12 = NULL;
DWORD length;
RET_IF_FAILED(pSample->ConvertToContiguousBuffer(&mediaBuffer), "Could not convert IMFSample to contagiuous buffer", E_FAIL);
RET_IF_FAILED(mediaBuffer->GetCurrentLength(&length), "Could not get buffer length", E_FAIL);
RET_IF_FAILED(mediaBuffer->Lock(&pDataNV12, NULL, NULL), "Could not lock the buffer", E_FAIL);
BYTE *pDataYUV420P = new BYTE[length];
this->convertNV12toYUV420P(pDataNV12, pDataYUV420P, this->width, this->height);
RET_IF_FAILED(av_image_fill_arrays(frame->data, frame->linesize, pDataYUV420P, pixelFormat, this->width, this->height, 1), "Could not fill the frame with data from the buffer", E_FAIL);
LOG_IF_FAILED(mediaBuffer->Unlock(), "Could not unlock the buffer");
frame->pts = av_rescale_q(this->pts++, this->codecContext->time_base, this->stream->time_base);
AVPacket pkt;
av_init_packet(&pkt);
pkt.data = NULL;
pkt.size = 0;
RET_IF_FAILED_AV(avcodec_send_frame(this->codecContext, frame), "Could not send the frame to the encoder", E_FAIL);
delete[] pDataYUV420P;
if (SUCCEEDED(avcodec_receive_packet(this->codecContext, &pkt))) {
RET_IF_FAILED_AV(av_interleaved_write_frame(this->fmtContext, &pkt), "Could not write the received packet.", E_FAIL);
}
av_packet_unref(&pkt);
return S_OK;
}
HRESULT Session::endSession() {
LOG("Ending session...");
LOG("Closing files...")
LOG_IF_FAILED_AV(av_write_trailer(this->fmtContext), "Could not finalize the output file.");
LOG_IF_FAILED_AV(avio_close(this->fmtContext->pb), "Could not close the output file.");
LOG_IF_FAILED_AV(avcodec_close(this->codecContext), "Could not close the codec.");
av_free(this->codecContext);
LOG("Done.")
return S_OK;
}
的問題是生成的文件無法在VLC或MPC-HC中播放。然而，按照文件屬性信息MPC-HC報道：
General
Unique ID : 202978442142665779317960161865934977227 (0x98B439D9BE859109BD5EC00A62A238CB)
Complete name : T:\Test.mkv
Format : Matroska
Format version : Version 4/Version 2
File size : 24.6 MiB
Duration : 147ms
Overall bit rate : 1 401 Mbps
Writing application : Lavf57.57.100
Writing library : Lavf57.57.100
Video
ID : 1
Format : FFV1
Format version : Version 0
Codec ID : V_MS/VFW/FOURCC/FFV1
Duration : 147ms
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 1 000.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Compression mode : Lossless
Default : Yes
Forced : No
DURATION : 00:00:00.147000000
coder_type : Golomb Rice
一些需要注意的是，它報告1000 FPS，因爲我已經在代碼中設置AVCodecContext::time_base這是奇怪的。
更新1：
我設法通過設置流的time_base屬性設置正確的FPS：
this->stream->time_base.den = fps_num;
this->stream->time_base.num = fps_den;
VLC播放輸出的文件，但它顯示的不是視頻VLC的標誌，就好像文件中沒有視頻流一樣。
更新2：
整理了的代碼。現在如果我設置codecId = AV_CODEC_ID_MPEG2VIDEO輸出文件有效並在VLC和MPC-HC中播放。與FFV1編碼的文件中使用ffprobe產生以下結果：
C:\root\apps\ffmpeg>ffprobe.exe t:\test.avi
ffprobe version 3.2 Copyright (c) 2007-2016 the FFmpeg developers
built with gcc 5.4.0 (GCC)
configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-libebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
libavutil 55. 34.100/55. 34.100
libavcodec 57. 64.100/57. 64.100
libavformat 57. 56.100/57. 56.100
libavdevice 57. 1.100/57. 1.100
libavfilter 6. 65.100/6. 65.100
libswscale 4. 2.100/4. 2.100
libswresample 2. 3.100/2. 3.100
libpostproc 54. 1.100/54. 1.100
[ffv1 @ 00000000006b83a0] read_quant_table error
Input #0, avi, from 't:\test.avi':
Metadata:
encoder : Lavf57.56.100
Duration: 00:00:04.94, start: 0.000000, bitrate: 107005 kb/s
Stream #0:0: Video: ffv1 (FFV1/0x31564646), yuv420p, 1280x720, 107717 kb/s, 29.97 fps, 29.97 tbr, 29.97 tbn, 29.97 tbc