A类似问题在其他地方被询问过没有一个让我满意的答案。
以下 ffmpeg 命令导致错误。当添加“-c:a copy”以仅复制音频流时，视频流会以请求的比特率很好地重新编码。
我在 OS X Yosemite 10.10.2 上运行它。
该错误该如何解决？
ffmpeg -i input.mp4 -b:v 8M -b:a 10k output.mp4
ffmpeg version 1.0.1 Copyright (c) 2000-2012 the FFmpeg developers
built on Dec 7 2012 09:31:51 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
configuration: --prefix=/Volumes/Ramdisk/sw --enable-gpl --enable-pthreads --enable-version3 --enable-libspeex --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-avfilter --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-filters --enable-libgsm --arch=x86_64 --enable-runtime-cpudetect
libavutil 51. 73.101 / 51. 73.101
libavcodec 54. 59.100 / 54. 59.100
libavformat 54. 29.104 / 54. 29.104
libavdevice 54. 2.101 / 54. 2.101
libavfilter 3. 17.100 / 3. 17.100
libswscale 2. 1.101 / 2. 1.101
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
Metadata:
major_brand : mp42
minor_version : 1
compatible_brands: mp41mp42isom
creation_time : 2015-02-06 08:37:52
Duration: 00:00:48.04, start: 0.000000, bitrate: 12332 kb/s
Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1920x960 [SAR 1:1 DAR 2:1], 12201 kb/s, 14.98 fps, 14.99 tbr, 600 tbn, 1200 tbc
Metadata:
creation_time : 2015-02-06 08:37:52
handler_name : Core Media Video
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, s16, 125 kb/s
Metadata:
creation_time : 2015-02-06 08:37:52
handler_name : Core Media Audio
[libx264 @ 0x7fbbba009c00] using SAR=1/1
[libx264 @ 0x7fbbba009c00] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.1 Cache64
[libx264 @ 0x7fbbba009c00] profile High, level 4.0
[libx264 @ 0x7fbbba009c00] 264 - core 128 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=14 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=8000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[NULL @ 0x7fbbba00aa00] Codec is experimental but experimental codecs are not enabled, try -strict -2
Output #0, mp4, to 'output.mp4':
Metadata:
major_brand : mp42
minor_version : 1
compatible_brands: mp41mp42isom
Stream #0:0(und): Video: h264, yuv420p, 1920x960 [SAR 1:1 DAR 2:1], q=-1--1, 8000 kb/s, 90k tbn, 14.99 tbc
Metadata:
creation_time : 2015-02-06 08:37:52
handler_name : Core Media Video
Stream #0:1(und): Audio: none, 44100 Hz, mono, flt, 10 kb/s
Metadata:
creation_time : 2015-02-06 08:37:52
handler_name : Core Media Audio
Stream mapping:
Stream #0:0 -> #0:0 (h264 -> libx264)
Stream #0:1 -> #0:1 (aac -> aac)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height
答案1
这是你的错误：
编解码器处于实验阶段，但实验性编解码器尚未启用，请尝试 -strict -2
转换为 MP4 时，ffmpeg 会尝试选择 AAC 音频编码器。由于您的 ffmpeg 未使用 或 （均为第三方编码器）进行编译libfaac，libfdk-aac因此libvo-aacenc它默认使用内部 AAC 编码器（称为aac）。
但是，此编码器在您构建的 ffmpeg 中被视为实验性的，并且仅当您在选项中添加-strict -2或时才会运行。-strict experimental
一些说明：