错误： H.264 bitstream malformed, no startcode found,

使用命令　ffmpeg -i hｂｇ.flv -c copy hbg.ts

时遇到如下错误：

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：

主要是因为使用了mp4中的h264编码，而h264有两种封装：
一种是annexb模式，传统模式，有startcode，SPS和PPS是在ES中；另一种是mp4模式，一般mp4、mkv、avi会没有startcode，SPS和PPS以及其它信息被封装在container中，每一个frame前面是这个frame的长度，很多解码器只支持annexb这种模式，因此需要将mp4做转换；在ffmpeg中用h264_mp4toannexb_filter可以做转换；所以需要使用-bsf h264_mp4toannexb来进行转换；

因此，将命令修改为如下后，可得到正确的结果

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%