我在 Quicktime 容器中有一个视频。Ubuntu 文件属性和以下信息中报告了此问题ffprobe：
>ffprobe -show_format test.mov
...
[FORMAT]
filename=test.mov
nb_streams=1
nb_programs=0
format_name=mov,mp4,m4a,3gp,3g2,mj2
format_long_name=QuickTime / MOV
start_time=0.000000
duration=300.066667
size=24226600
bit_rate=645899
probe_score=100
TAG:major_brand=mp42
TAG:minor_version=0
TAG:compatible_brands=mp42mp41isomiso2
TAG:creation_time=2020-09-17T10:31:26.000000Z
TAG:encoder=x264
[/FORMAT]
将容器转换为mp4不会产生任何错误。
>ffmpeg -i test.mov -c copy test.mp4
ffmpeg version 3.4.8-0ubuntu0.2 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
configuration: --prefix=/usr --extra-version=0ubuntu0.2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --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-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --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-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
WARNING: library configuration mismatch
avcodec configuration: --prefix=/usr --extra-version=0ubuntu0.2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --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-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --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-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared --enable-version3 --disable-doc --disable-programs --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc
libavutil 55. 78.100 / 55. 78.100
libavcodec 57.107.100 / 57.107.100
libavformat 57. 83.100 / 57. 83.100
libavdevice 57. 10.100 / 57. 10.100
libavfilter 6.107.100 / 6.107.100
libavresample 3. 7. 0 / 3. 7. 0
libswscale 4. 8.100 / 4. 8.100
libswresample 2. 9.100 / 2. 9.100
libpostproc 54. 7.100 / 54. 7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mov':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42mp41isomiso2
creation_time : 2020-09-17T10:31:26.000000Z
encoder : x264
Duration: 00:05:00.07, start: 0.000000, bitrate: 645 kb/s
Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p(tv, bt709), 1442x906 [SAR 1:1 DAR 721:453], 645 kb/s, 15 fps, 15 tbr, 1500 tbn, 30 tbc (default)
Metadata:
creation_time : 2020-09-17T10:31:26.000000Z
handler_name : VideoHandler
File 'test.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'test.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42mp41isomiso2
encoder : Lavf57.83.100
Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p(tv, bt709), 1442x906 [SAR 1:1 DAR 721:453], q=2-31, 645 kb/s, 15 fps, 15 tbr, 12k tbn, 1500 tbc (default)
Metadata:
creation_time : 2020-09-17T10:31:26.000000Z
handler_name : VideoHandler
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame= 4501 fps=0.0 q=-1.0 Lsize= 23659kB time=00:05:00.00 bitrate= 646.1kbits/s speed=6.04e+03x
video:23640kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.079859%
但格式没有改变。至少 Quicktime 容器在 Ubuntu 文件属性和 ffprobe 中都有显示：
ffprobe -show_format test.mp4
[FORMAT]
filename=test.mp4
nb_streams=1
nb_programs=0
format_name=mov,mp4,m4a,3gp,3g2,mj2
format_long_name=QuickTime / MOV
start_time=0.000000
duration=300.067000
size=24226885
bit_rate=645906
probe_score=100
TAG:major_brand=isom
TAG:minor_version=512
TAG:compatible_brands=isomiso2avc1mp41
TAG:encoder=Lavf57.83.100
[/FORMAT]
但是正如您在上面的命令输出中看到的，ffmpeg使用的编码器从 更改mp4为Lavf57.83.100。
这是我的版本ffmpeg
ffmpeg -version
ffmpeg version 3.4.8-0ubuntu0.2 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
configuration: --prefix=/usr --extra-version=0ubuntu0.2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --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-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --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-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
libavutil 55. 78.100 / 55. 78.100
libavcodec 57.107.100 / 57.107.100
libavformat 57. 83.100 / 57. 83.100
libavdevice 57. 10.100 / 57. 10.100
libavfilter 6.107.100 / 6.107.100
libavresample 3. 7. 0 / 3. 7. 0
libswscale 4. 8.100 / 4. 8.100
libswresample 2. 9.100 / 2. 9.100
libpostproc 54. 7.100 / 54. 7.100
答案1
MP4 及其系列格式（ISO Base Media）源自 Apple Quicktime。由于它们的结构基本相同，因此 FFmpeg 只有一个用于 Quicktime 和 ISO Base Media 系列格式的解复用器和复用器。它的全名QuickTime / MOV如您所见。
识别MOV或MP4的方法是看主要品牌。
对于您的来源，它TAG:major_brand=mp42表示的是 ISO 14496 Part 14(MP4 v2)，而不是 Quicktime，无论扩展名是什么。
对于生成的文件，它是TAG:major_brand=isom，表示ISO 14496 Part 12哪个是 ISO 基本媒体文件格式，也就是常规 MP4 应该是什么格式。
答案2
尝试运行
ffmpeg -i test.mov -vcodec copy -acodec copy test.mp4
或者，你可以用最佳质量重新编码
ffmpeg -i test.mov -q:v 0 test.mp4