我正在试验 FFMPEG 命令将任何视频格式转换为 mp4。
服务器管理员执行我创建的以下命令并向我显示错误：
ffmpeg -ss 00:03:00 -i /video/1444107854.mov -c:v libx264 /video/player/1444107854.mp4 -vframes 1 /video/thumb/1444107854.jpg
这是错误：
[aac @ 0x2b845a0] 编码器“aac”是实验性的，但未启用实验性编解码器，如果要使用它，请添加“-strict -2”。
我怎样才能避免这个错误以及实验性编解码器，所以如果我明确指定它，任何人都可以让我知道什么是最好的编解码器。
我的ffmpeg和服务器如下：
ffmpeg 版本 N-75903-g14573b9 版权所有 (c) 2000-2015 FFmpeg 开发人员使用 gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-16) 构建
编辑1：我稍微更改了命令并添加 -c:a copy 以按原样复制音频流，但仍然没有希望：
新命令：
ffmpeg -ss 00:03:00 -i /video/1444107854.mov -c:v libx264 -c:a copy /video/player/1444107854.mp4 -vframes 1 /video/thumb/1444107854.jpg
执行此操作后，我得到了一个 23k 大小的文件，显然在日志中它只复制音频流，最终输出中没有添加视频。其日志如下：
> ffmpeg version N-75903-g14573b9 Copyright (c) 2000-2015 the FFmpeg
> developers built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-16)
> configuration: --enable-libx264 --enable-gpl libavutil 55.
> 3.100 / 55. 3.100 libavcodec 57. 5.100 / 57. 5.100 libavformat 57. 3.100 / 57. 3.100 libavdevice 57. 0.100 /
> 57. 0.100 libavfilter 6. 10.100 / 6. 10.100 libswscale 4. 0.100 / 4. 0.100 libswresample 2. 0.100 / 2. 0.100 libpostproc 54. 0.100 / 54. 0.100 Input #0, mpeg, from
> '/video/1444108714.mpg':
> Duration: 00:00:02.14, start: 0.184278, bitrate: 15689 kb/s
> Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], max. 38810 kb/s, 29.97 fps, 29.97 tbr,
> 90k tbn, 59.94 tbc
> Stream #0:1[0x80]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s [swscaler @ 0x347fda0] deprecated pixel format used, make sure you did
> set range correctly [libx264 @ 0x34708a0] using SAR=1/1 [libx264 @
> 0x34708a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 [libx264
> @ 0x34708a0] profile High, level 4.0 [libx264 @ 0x34708a0] 264 - core
> 148 r2597 e86f3a1 - H.264/MPEG-4 AVC codec - Copyleft 2003-2015 -
> 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=34
> lookahead_threads=5 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=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf
> mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40
> aq=1:1.00 [mp4 @ 0x346f6c0] Codec for stream 1 does not use global
> headers but container format requires global headers [mp4 @ 0x346f6c0]
> track 1: codec frame size is not set Output #0, mp4, to
> '/video/player/1444108714.mp4':
> Metadata:
> encoder : Lavf57.3.100
> Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 29.97 fps, 30k tbn,
> 29.97 tbc
> Metadata:
> encoder : Lavc57.5.100 libx264
> Stream #0:1: Audio: ac3 ([165][0][0][0] / 0x00A5), 48000 Hz, 5.1(side), 448 kb/s Output #1, image2, to '/video/thumb/1444108714.jpg':
> Metadata:
> encoder : Lavf57.3.100
> Stream #1:0: Video: mjpeg, yuvj420p(pc), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 29.97 fps, 29.97 tbn, 29.97 tbc
> Metadata:
> encoder : Lavc57.5.100 mjpeg Stream mapping: Stream #0:0 -> #0:0 (mpeg2video (native) -> h264 (libx264)) Stream #0:1 -> #0:1 (copy) Stream #0:0 -> #1:0 (mpeg2video (native) -> mjpeg (native)) Press [q] to stop, [?] for help [mp4 @ 0x346f6c0]
> Non-monotonous DTS in output stream 0:1; previous: 2208, current: 672;
> changing to 2209. This may result in incorrect timestamps in the
> output file. frame= 0 fps=0.0 q=0.0 Lq=0.0 size= 23kB
> time=00:00:00.07 bitrate=2447.5kbits/s video:0kB audio:23kB
> subtitle:0kB other streams:0kB global headers:0kB muxing overhead:
> 3.457839%
编辑2：
ffmpeg -y -i ./1445675270.m4b -c:v libx264 -crf 20 -preset slow -pix_fmt yuv420p -movflags +faststart -c:a libfdk_aac -b:a 128k ./player/1445675270.mp4 -vframes 1 ./thumb/1445675270.jpg
以上命令输出以下消息，如果您能提出建议，我将不胜感激。
ffmpeg version git-2015-10-11-49f4967 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-16)
configuration: --prefix=/root/ffmpeg_build --extra-cflags=-I/root/ffmpeg_build/include --extra-ldflags=-L/root/ffmpeg_build/lib --bindir=/root/bin --pkg-config-flags=--static --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
libavutil 55. 3.100 / 55. 3.100
libavcodec 57. 5.100 / 57. 5.100
libavformat 57. 3.100 / 57. 3.100
libavdevice 57. 0.100 / 57. 0.100
libavfilter 6. 11.100 / 6. 11.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.100 / 2. 0.100
libpostproc 54. 0.100 / 54. 0.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x31e07c0] stream 0, timescale not set
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from './1445675270.m4b':
Metadata:
major_brand : M4A
minor_version : 0
compatible_brands: M4A mp42isom
creation_time : 2005-08-01 07:26:16
tool : ?
title : MAKE_2005-08-01
artist : MAKE Magazine
composer : MAKE Magazine - Phillip Torrone
album : Interview with Janus Wireless
grouping : MAKE Magazine enhanced podcast
genre : Podcast
date : 2005
comment : Interview with Janus wireless and their 5 Wi-Fi card packet capturing Linux box. This is a special enhanced podcast (this file plays images and links in iTunes and on iPod color devices).
Duration: 00:02:57.54, start: 0.000000, bitrate: 162 kb/s
Chapter #0:0: start 0.000000, end 17.000000
Metadata:
title : MAKE Magazine @ DEFCON with JANUS
Chapter #0:1: start 17.000000, end 37.000000
Metadata:
title : Janus
Chapter #0:2: start 37.000000, end 83.000000
Metadata:
title : Construction
Chapter #0:3: start 83.000000, end 109.000000
Metadata:
title : The MAKERs
Chapter #0:4: start 109.000000, end 177.540000
Metadata:
title : Display
Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 22050 Hz, mono, fltp, 32 kb/s (default)
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
Stream #0:1(eng): Subtitle: mov_text (text / 0x74786574), 0 kb/s
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
Stream #0:2(eng): Video: tiff (tiff / 0x66666974), rgb24, 167x166, 126 kb/s, SAR 206:275 DAR 17201:22825, 0.03 fps, 1 tbr, 22050 tbn, 22050 tbc (default)
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
encoder : TIFF (Uncompressed)
Stream #0:3(eng): Subtitle: mov_text (tx3g / 0x67337874), 160x160, 0 kb/s (default)
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
Stream #0:4: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 167x166 [SAR 1:1 DAR 167:166], 90k tbr, 90k tbn, 90k tbc
[swscaler @ 0x3242360] deprecated pixel format used, make sure you did set range correctly
[libx264 @ 0x3228c40] width not divisible by 2 (167x166)
Output #0, mp4, to './player/1445675270.mp4':
Metadata:
major_brand : M4A
minor_version : 0
compatible_brands: M4A mp42isom
comment : Interview with Janus wireless and their 5 Wi-Fi card packet capturing Linux box. This is a special enhanced podcast (this file plays images and links in iTunes and on iPod color devices).
tool : ?
title : MAKE_2005-08-01
artist : MAKE Magazine
composer : MAKE Magazine - Phillip Torrone
album : Interview with Janus Wireless
grouping : MAKE Magazine enhanced podcast
genre : Podcast
date : 2005
Chapter #0:0: start 0.000000, end 17.000000
Metadata:
title : MAKE Magazine @ DEFCON with JANUS
Chapter #0:1: start 17.000000, end 37.000000
Metadata:
title : Janus
Chapter #0:2: start 37.000000, end 83.000000
Metadata:
title : Construction
Chapter #0:3: start 83.000000, end 109.000000
Metadata:
title : The MAKERs
Chapter #0:4: start 109.000000, end 177.540000
Metadata:
title : Display
Stream #0:0(eng): Video: h264, none, q=2-31, 128 kb/s, SAR 206:275 DAR 0:0, 1 fps (default)
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
encoder : Lavc57.5.100 libx264
Stream #0:1(eng): Audio: aac, 0 channels, 128 kb/s (default)
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
encoder : Lavc57.5.100 libfdk_aac
Output #1, image2, to './thumb/1445675270.jpg':
Metadata:
major_brand : M4A
minor_version : 0
compatible_brands: M4A mp42isom
comment : Interview with Janus wireless and their 5 Wi-Fi card packet capturing Linux box. This is a special enhanced podcast (this file plays images and links in iTunes and on iPod color devices).
tool : ?
title : MAKE_2005-08-01
artist : MAKE Magazine
composer : MAKE Magazine - Phillip Torrone
album : Interview with Janus Wireless
grouping : MAKE Magazine enhanced podcast
genre : Podcast
date : 2005
Chapter #1:0: start 0.000000, end 17.000000
Metadata:
title : MAKE Magazine @ DEFCON with JANUS
Chapter #1:1: start 17.000000, end 37.000000
Metadata:
title : Janus
Chapter #1:2: start 37.000000, end 83.000000
Metadata:
title : Construction
Chapter #1:3: start 83.000000, end 109.000000
Metadata:
title : The MAKERs
Chapter #1:4: start 109.000000, end 177.540000
Metadata:
title : Display
Stream #1:0(eng): Video: mjpeg, none, q=2-31, 128 kb/s, SAR 206:275 DAR 0:0, 1 fps (default)
Metadata:
creation_time : 2005-08-01 07:26:16
handler_name : ?Apple Alias Data Handler
encoder : Lavc57.5.100 mjpeg
Stream mapping:
Stream #0:2 -> #0:0 (tiff (native) -> h264 (libx264))
Stream #0:0 -> #0:1 (aac (native) -> aac (libfdk_aac))
Stream #0:2 -> #1:0 (tiff (native) -> mjpeg (native))
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height