为什么ffmpeg无法将this.ts转成.mp4

Question

我的 Synology NAS 上运行着 ffmpeg，我想用它来将 DVR-recorded.ts 视频转换成.mp4 格式。 我对这东西不是很了解，研究了也无济于事。

这是我运行的命令，结果是：

$ ffmpeg -analyzeduration 2147483647 -probesize 2147483647 -i 'video.ts' -acodec -vcodec copy 'video.mp4'

ffmpeg version 4.1.8 Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 8.5.0 (GCC)
  configuration: --prefix=/usr --incdir='${prefix}/include/ffmpeg' --arch=i686 --target-os=linux --cross-prefix=/usr/local/x86_64-pc-linux-gnu/bin/x86_64-pc-linux-gnu- --enable-cross-compile --enable-optimizations --enable-pic --enable-gpl --enable-shared --disable-static --disable-stripping --enable-version3 --enable-encoders --enable-pthreads --disable-protocols --disable-protocol=rtp --enable-protocol=file --enable-protocol=pipe --disable-muxer=image2 --disable-muxer=image2pipe --disable-swscale-alpha --disable-ffplay --disable-ffprobe --disable-doc --disable-devices --disable-bzlib --disable-altivec --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libmp3lame --disable-vaapi --disable-cuvid --disable-nvenc --disable-decoder=aac --disable-decoder=aac_fixed --disable-encoder=aac --disable-decoder=amrnb --disable-decoder=ac3 --disable-decoder=ac3_fixed --disable-encoder=zmbv --disable-encoder=dca --disable-decoder=dca --disable-encoder=ac3 --disable-encoder=ac3_fixed --disable-encoder=eac3 --disable-decoder=eac3 --disable-encoder=truehd --disable-decoder=truehd --disable-encoder=hevc_vaapi --disable-decoder=hevc --disable-muxer=hevc --disable-demuxer=hevc --disable-parser=hevc --disable-bsf=hevc_mp4toannexb --x86asmexe=yasm --cc=/usr/local/x86_64-pc-linux-gnu/bin/x86_64-pc-linux-gnu-wrap-gcc --enable-yasm --enable-libx264 --enable-encoder=libx264
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[mpegts @ 0x5591c4feb4c0] Could not find codec parameters for stream 1 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels, 199 kb/s): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mpegts, from 'video.ts':
  Duration: 02:01:58.77, start: 1.405122, bitrate: 4094 kb/s
  Program 1 
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
    Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], Closed Captions, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
    Stream #0:1[0x101]: Audio: aac ([15][0][0][0] / 0x000F), 0 channels, 199 kb/s
[NULL @ 0x5591c6034980] Unable to find a suitable output format for 'copy'
copy: Invalid argument

这是 VLC 中显示的来自 video.ts 的信息：

媒体资讯

可能我的 ffmpeg 包装中没有包含正确的编码器（从https://synocommunity.com/package/ffmpeg获得）。 这是我拥有的音频编码器。

A..... adpcm_adx            SEGA CRI ADX ADPCM
 A..... g722                 G.722 ADPCM (codec adpcm_g722)
 A..... g726                 G.726 ADPCM (codec adpcm_g726)
 A..... g726le               G.726 little endian ADPCM ("right-justified") (codec adpcm_g726le)
 A..... adpcm_ima_qt         ADPCM IMA QuickTime
 A..... adpcm_ima_wav        ADPCM IMA WAV
 A..... adpcm_ms             ADPCM Microsoft
 A..... adpcm_swf            ADPCM Shockwave Flash
 A..... adpcm_yamaha         ADPCM Yamaha
 A..... alac                 ALAC (Apple Lossless Audio Codec)
 A..... libopencore_amrnb    OpenCORE AMR-NB (Adaptive Multi-Rate Narrow-Band) (codec amr_nb)
 A..... aptx                 aptX (Audio Processing Technology for Bluetooth)
 A..... aptx_hd              aptX HD (Audio Processing Technology for Bluetooth)
 A..... comfortnoise         RFC 3389 comfort noise generator
 A..... flac                 FLAC (Free Lossless Audio Codec)
 A..... g723_1               G.723.1
 A..X.. mlp                  MLP (Meridian Lossless Packing)
 A..... mp2                  MP2 (MPEG audio layer 2)
 A..... mp2fixed             MP2 fixed point (MPEG audio layer 2) (codec mp2)
 A..... libmp3lame           libmp3lame MP3 (MPEG audio layer 3) (codec mp3)
 A..... nellymoser           Nellymoser Asao
 A..X.. opus                 Opus
 A..... pcm_alaw             PCM A-law / G.711 A-law
 A..... pcm_f32be            PCM 32-bit floating point big-endian
 A..... pcm_f32le            PCM 32-bit floating point little-endian
 A..... pcm_f64be            PCM 64-bit floating point big-endian
 A..... pcm_f64le            PCM 64-bit floating point little-endian
 A..... pcm_mulaw            PCM mu-law / G.711 mu-law
 A..... pcm_s16be            PCM signed 16-bit big-endian
 A..... pcm_s16be_planar     PCM signed 16-bit big-endian planar
 A..... pcm_s16le            PCM signed 16-bit little-endian
 A..... pcm_s16le_planar     PCM signed 16-bit little-endian planar
 A..... pcm_s24be            PCM signed 24-bit big-endian
 A..... pcm_s24daud          PCM D-Cinema audio signed 24-bit
 A..... pcm_s24le            PCM signed 24-bit little-endian
 A..... pcm_s24le_planar     PCM signed 24-bit little-endian planar
 A..... pcm_s32be            PCM signed 32-bit big-endian
 A..... pcm_s32le            PCM signed 32-bit little-endian
 A..... pcm_s32le_planar     PCM signed 32-bit little-endian planar
 A..... pcm_s64be            PCM signed 64-bit big-endian
 A..... pcm_s64le            PCM signed 64-bit little-endian
 A..... pcm_s8               PCM signed 8-bit
 A..... pcm_s8_planar        PCM signed 8-bit planar
 A..... pcm_u16be            PCM unsigned 16-bit big-endian
 A..... pcm_u16le            PCM unsigned 16-bit little-endian
 A..... pcm_u24be            PCM unsigned 24-bit big-endian
 A..... pcm_u24le            PCM unsigned 24-bit little-endian
 A..... pcm_u32be            PCM unsigned 32-bit big-endian
 A..... pcm_u32le            PCM unsigned 32-bit little-endian
 A..... pcm_u8               PCM unsigned 8-bit
 A..... pcm_vidc             PCM Archimedes VIDC
 A..... real_144             RealAudio 1.0 (14.4K) (codec ra_144)
 A..... roq_dpcm             id RoQ DPCM
 A..X.. s302m                SMPTE 302M
 A..... sbc                  SBC (low-complexity subband codec)
 A..X.. sonic                Sonic
 A..X.. sonicls              Sonic lossless
 A..... tta                  TTA (True Audio)
 A..X.. vorbis               Vorbis
 A..... wavpack              WavPack
 A..... wmav1                Windows Media Audio 1
 A..... wmav2                Windows Media Audio 2

Answer 1

我要回答我自己的问题，因为我终于想通了，并认为这可能对将来的其他人有用。

似乎来自https://synocommunity.com/package/ffmpeg的 Synology ffmpeg package 已使用以下标志编译：

--disable-decoder=aac_fixed --disable-encoder=aac

现在我不知道为什么它是这样编译的，但 .net 的结果是它似乎无法解码 AAC 音频，这是这个特定视频文件包含的内容。

我找到了一个 docker 图像并运行它，它工作正常。 docker 图像具有：

--enable-libfdk_aac

这似乎改变了世界！

Answer 2

您的命令不包含音频编解码器： -acodec -vcodec copy $outputfile被解释为“使用 -vcodec 作为音频编解码器，并将 copy 和 $outputfile 用作 output 文件”。 你想使用-acodec copy -vcodec copy $outputfile ，所以它只将编解码器和输出复制到文件$outputfile 。