使用命令 ffmpeg -i hｂｇ.flv -c copy hbg.ts
時遇到如下錯誤：
ffmpeg version 2.8.15-0ubuntu0.16.04.1 Copyright (c) 2000-2018 the FFmpeg developers
built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609
configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
libavutil 54. 31.100 / 54. 31.100
libavcodec 56. 60.100 / 56. 60.100
libavformat 56. 40.101 / 56. 40.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 40.101 / 5. 40.101
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.101 / 1. 2.101
libpostproc 53. 3.100 / 53. 3.100
Input #0, flv, from 'hｂｇ.flv':
Metadata:
encoder : Lavf58.20.100
Duration: 00:00:15.43, start: 0.000000, bitrate: 755 kb/s
Stream #0:0: Video: h264 (High), yuv420p, 800x450, 24.42 fps, 23.98 tbr, 1k tbn, 47.95 tbc
Stream #0:1: Audio: aac (LC), 44100 Hz, stereo, fltp
File 'hbg.ts' already exists. Overwrite ? [y/N] y
Output #0, mpegts, to 'hbg.ts':
Metadata:
encoder : Lavf56.40.101
Stream #0:0: Video: h264, yuv420p, 800x450, q=2-31, 24.42 fps, 23.98 tbr, 90k tbn, 1k tbc
Stream #0:1: Audio: aac, 44100 Hz, stereo
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
[mpegts @ 0x18b12a0] H.264 bitstream malformed, no startcode found, use the video bitstream filter 'h264_mp4toannexb' to fix it ('-bsf:v h264_mp4toannexb' option with ffmpeg)
av_interleaved_write_frame(): Invalid data found when processing input
frame= 1 fps=0.0 q=-1.0 Lsize= 1kB time=00:00:00.02 bitrate= 388.6kbits/s
video:19kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Conversion failed!
搜索后得知：
主要是因為使用了mp4中的h264編碼，而h264有兩種封裝：
一種是annexb模式，傳統模式，有startcode，SPS和PPS是在ES中；另一種是mp4模式，一般mp4、mkv、avi會沒有startcode，SPS和PPS以及其它信息被封裝在container中，每一個frame前面是這個frame的長度，很多解碼器只支持annexb這種模式，因此需要將mp4做轉換；在ffmpeg中用h264_mp4toannexb_filter可以做轉換；所以需要使用-bsf h264_mp4toannexb來進行轉換；
因此，將命令修改為如下后，可得到正確的結果
ffmpeg -i hｂｇ.flv -c copy -bsf h264_mp4toannexb hbg.ts
ffmpeg version 2.8.15-0ubuntu0.16.04.1 Copyright (c) 2000-2018 the FFmpeg developers
built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609
configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
libavutil 54. 31.100 / 54. 31.100
libavcodec 56. 60.100 / 56. 60.100
libavformat 56. 40.101 / 56. 40.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 40.101 / 5. 40.101
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.101 / 1. 2.101
libpostproc 53. 3.100 / 53. 3.100
Input #0, flv, from 'hbg.flv':
Metadata:
encoder : Lavf58.20.100
Duration: 00:00:15.43, start: 0.000000, bitrate: 755 kb/s
Stream #0:0: Video: h264 (High), yuv420p, 800x450, 24.42 fps, 23.98 tbr, 1k tbn, 47.95 tbc
Stream #0:1: Audio: aac (LC), 44100 Hz, stereo, fltp
File 'hbg.ts' already exists. Overwrite ? [y/N] y
Output #0, mpegts, to 'hbg.ts':
Metadata:
encoder : Lavf56.40.101
Stream #0:0: Video: h264, yuv420p, 800x450, q=2-31, 24.42 fps, 23.98 tbr, 90k tbn, 1k tbc
Stream #0:1: Audio: aac, 44100 Hz, stereo
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 366 fps=0.0 q=-1.0 Lsize= 1580kB time=00:00:15.23 bitrate= 849.5kbits/s
video:1171kB audio:234kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 12.494288%