ffmpeg命令行参数设定解说
ffmpeg参数设定解说
-bitexact 使用标准比特率
-vcodec xvid 使用xvid压缩
-s 320x240 指定分辨率
-r 29.97 桢速率（可以改，确认非标准桢率会导致音画不同步，所以只能设定为15或者29.97）
画面部分，选其一
-b <比特率> 指定压缩比特率，似乎ffmpeg是自动VBR的，指定了就大概是平均比特率，比如768，1500这样的就是原来默认项目中有的
-qscale <数值> 以<数值>质量为基础的VBR，取值0.01-255，约小质量越好
-qmin <数值> 设定最小质量，与-qmax（设定最大质量）共用，比如-qmin 10 -qmax 31
-sameq 使用和源同样的质量
声音部分
-acodec aac 设定声音编码
-ac <数值> 设定声道数，1就是单声道，2就是立体声，转换单声道的TVrip可以用1（节省一半容量），高品质的DVDrip就可以用2
-ar <采样率> 设定声音采样率，PSP只认24000
-ab <比特率> 设定声音比特率，前面-ac设为立体声时要以一半比特率来设置，比如192kbps的就设成96，转换君默认比特率都较小，要听到较高品质声音的话建议设到160kbps（80）以上
-vol <百分比> 设定音量，某些DVDrip的AC3轨音量极小，转换时可以用这个提高音量，比如200就是原来的2倍
这样，要得到一个高画质音质低容量的MP4的话，首先画面最好不要用固定比特率，而用VBR参数让程序自己去判断，而音质参数可以在原来的基础上提升一点，听起来要舒服很多，也不会太大（看情况调整）
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ffmpeg的使用[zt]
先从ffmpeg开始。
上有说明，音视频的分离，转换，解码的完全解决方案。
其中最重要的就是libavcodec库。它被mplayer或者xine使用作为解码器。还有，国内比较流行的播放器影音风暴或MyMPC的后端ffdshow也是使用ffmpeg的解码库的。
ffmpeg包括一组软件，ffmpeg用于对媒体文件进行处理，ffserver是一个http的流媒体服务器，ffplay是一个基于SDL的简单播放器。两个库文件libavcodec和libavformat。
ffmpeg作为媒体文件处理软件，基本用法如下：
ffmpeg -i INPUTfile [OPTIONS] OUTPUTfile
输入输出文件通常就是待处理的多媒体文件了。可以是纯粹的音频文件，纯粹的视频文件，或者混合的。
大部分常见的格式都能够“通杀”。象常见的各种mpeg，AVI封装的DIVX和Xvid等等
具体的格式支持列表可以使用ffmpeg -formats查看或直接查阅文档。
另：由于Linux把设备视为文件，因此－i选项后可以跟设备名。比如DV，视频卡，光驱或者其它的各类设备。
输出的内容通过Options调整。列出几个主要的选项
-vcodec 视频流编码方式
-b 视频流码率（默认只有200k，一般都需要手动设置，具体的数值视codec选择而定）
-r 视频流帧数（一般说来PAL制式通常用25，NTSC制式通常用29）
-s 视频解析度（分辨率，也要视codec和你的需要而定。通常改变某个视频流的解析度是很耗费CPU的事情。另：具体写法使用“数字x数字”的形式。中间是小写字母“x”，这个用过mplayer的应该都知道）
-t 处理持续时间。
-acodec 音频流编码方式
-ab 音频流码率（默认是同源文件码率，也需要视codec而定）
-ar 音频流采样率（大多数情况下使用44100和48000，分别对应PAL制式和NTSC制式，根据需要选择）
还有些可能需要用到的选项如
-vn和-an分别是屏蔽视频流和屏蔽音频流，分别对源文件处理一次即可得到分离的音频和视频
-author -title分别是设置媒体文件的作者和title
-f选项是强制使用某种格式
－target type是使用预置的格式转换（可以转成dvd，vcd或svcd）
除此之外还有些更高级的选项，如设定vbr，或设定high quality，或者设定vbr的buff和max/min码率，象一般我们自用的dvd抓轨啦，DV转vcd或dvd啦，网上下载的电影转成vcd或dvd都不一定需要用到它们。
具体的使用方法在man里面有介绍。简单明了。
少许使用经验：
1：ffmpeg对于rm的处理能力实在不敢恭维。也许是因为我主要使用二进制包安装的缘故，对于Real媒体格式只能处理老式的RV8编码的格式。而且效果不佳。
2：格式转换是一件很耗费CPU资源的事情。虽说ffmpeg已经比WinAVI啦，TmpgEnc这些win下的非专业级视频处理软件做的好些了。毕竟我们可以把ffmpeg运行的时候放到后台。
3：ffmpeg不是万能的，虽说支持的格式很多，但是如果你不是用的最新CVS出来的版本，可能碰上某些古怪的媒体文件就要郁闷。
4：ffmpeg全部是命令行操作。哪位达人写个GUI前端出来就可以让不少菜鸟脱离苦海了。还有就是不能批量处理，但是这个可以用shell帮忙解决。
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出现找不到lame的问题时，把libmp3lame-0.dll复制下就可以
//--------------------------------------------------------------------------------------------------------
下面为ffmpeg-0.4.9-p20051216的输出帮助文档：
ffmpeg version CVS, build 3342336, Copyright (c) 2000-2004 Fabrice Bellard
configuration: --enable-memalign-hack --enable-mingw32 --enable-mp3lame --
ra-cflags=-I/local/include --extra-ldflags=-L/local/lib
built on Jul 28 2006 14:50:53, gcc: 3.2.3 (mingw special 20030504-1)
usage: ffmpeg [[infile options] -i infile]... {[outfile options] outfile}...
Hyper fast Audio and Video encoder
Main options:
-L show license
-h show help
-version show version
-formats show available formats, codecs, protocols, ...
-f fmt force format
-img img_fmt force image format
-i filename input file name
-y overwrite output files
-t duration set the recording time
-fs limit_size set the limit file size
-ss time_off set the start time offset
-itsoffset time_off set the input ts offset
-title string set the title
-timestamp time set the timestamp
-author string set the author
-copyright string set the copyright
-comment string set the comment
-v verbose control amount of logging
-target type specify target file type ("vcd", "svcd", "dvd", "dv", "pa
cd", "ntsc-svcd", ...)
-dframes number set the number of data frames to record
-scodec codec force subtitle codec ('copy' to copy stream)
-newsubtitle add a new subtitle stream to the current output stream
-slang code set the ISO 639 language code (3 letters) of the current
title stream
Video options:
-b bitrate set video bitrate (in kbit/s)
-vframes number set the number of video frames to record
-r rate set frame rate (Hz value, fraction or abbreviation)
-s size set frame size (WxH or abbreviation)
-aspect aspect set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
-croptop size set top crop band size (in pixels)
-cropbottom size set bottom crop band size (in pixels)
-cropleft size set left crop band size (in pixels)
-cropright size set right crop band size (in pixels)
-padtop size set top pad band size (in pixels)
-padbottom size set bottom pad band size (in pixels)
-padleft size set left pad band size (in pixels)
-padright size set right pad band size (in pixels)
-padcolor color set color of pad bands (Hex 000000 thru FFFFFF)
-vn disable video
-bt tolerance set video bitrate tolerance (in kbit/s)
-maxrate bitrate set max video bitrate tolerance (in kbit/s)
-minrate bitrate set min video bitrate tolerance (in kbit/s)
-bufsize size set ratecontrol buffer size (in kByte)
-vcodec codec force video codec ('copy' to copy stream)
-sameq use same video quality as source (implies VBR)
-pass n select the pass number (1 or 2)
-passlogfile file select two pass log file name
-newvideo add a new video stream to the current output stream
Advanced Video options:
-pix_fmt format set pixel format
-g gop_size set the group of picture size
-intra use only intra frames
-vdt n discard threshold
-qscale q use fixed video quantiser scale (VBR)
-qmin q min video quantiser scale (VBR)
-qmax q max video quantiser scale (VBR)
-lmin lambda min video lagrange factor (VBR)
-lmax lambda max video lagrange factor (VBR)
-mblmin q min macroblock quantiser scale (VBR)
-mblmax q max macroblock quantiser scale (VBR)
-qdiff q max difference between the quantiser scale (VBR)
-qblur blur video quantiser scale blur (VBR)
-qsquish squish how to keep quantiser between qmin and qmax (0 = clip, 1
se differentiable function)
-qcomp compression video quantiser scale compression (VBR)
-rc_init_cplx complexity initial complexity for 1-pass encoding
-b_qfactor factor qp factor between p and b frames
-i_qfactor factor qp factor between p and i frames
-b_qoffset offset qp offset between p and b frames
-i_qoffset offset qp offset between p and i frames
-ibias bias intra quant bias
-pbias bias inter quant bias
-rc_eq equation set rate control equation
-rc_override override rate control override for specific intervals
-me method set motion estimation method
-me_threshold motion estimaton threshold
-mb_threshold macroblock threshold
-bf frames use 'frames' B frames
-preme pre motion estimation
-bug param workaround not auto detected encoder bugs
-strict strictness how strictly to follow the standards
-deinterlace deinterlace pictures
-psnr calculate PSNR of compressed frames
-vstats dump video coding statistics to file
-vhook module insert video processing module
-intra_matrix matrix specify intra matrix coeffs
-inter_matrix matrix specify inter matrix coeffs
-top top=1/bottom=0/auto=-1 field first
-sc_threshold threshold scene change threshold
-me_range range limit motion vectors range (1023 for DivX player)
-dc precision intra_dc_precision
-mepc factor (1.0 = 256) motion estimation bitrate penalty compensation
-vtag fourcc/tag force video tag/fourcc
-skip_threshold threshold frame skip threshold
-skip_factor factor frame skip factor
-skip_exp exponent frame skip exponent
-genpts generate pts
Audio options:
-aframes number set the number of audio frames to record
-ab bitrate set audio bitrate (in kbit/s)
-aq quality set audio quality (codec-specific)
-ar rate set audio sampling rate (in Hz)
-ac channels set number of audio channels
-an disable audio
-acodec codec force audio codec ('copy' to copy stream)
-vol volume change audio volume (256=normal)
-newaudio add a new audio stream to the current output stream
-alang code set the ISO 639 language code (3 letters) of the current aud
io stream
Advanced Audio options:
-atag fourcc/tag force audio tag/fourcc
Subtitle options:
-scodec codec force subtitle codec ('copy' to copy stream)
-newsubtitle add a new subtitle stream to the current output stream
-slang code set the ISO 639 language code (3 letters) of the current sub
title stream
Audio/Video grab options:
-vd device set video grab device
-vc channel set video grab channel (DV1394 only)
-tvstd standard set television standard (NTSC, PAL (SECAM))
-ad device set audio device
-grab format request grabbing using
-gd device set grab device
Advanced options:
-map file:stream[:syncfile:syncstream] set input stream mapping
-map_meta_data outfile:infile set meta data information of outfile from infile
-benchmark add timings for benchmarking
-dump dump each input packet
-hex when dumping packets, also dump the payload
-re read input at native frame rate
-loop loop (current only works with images)
-loop_output number of times to loop output in formats that support loopi
ng (0 loops forever)
-threads count thread count
-vsync video sync method
-async audio sync method
-vglobal video global header storage type
-copyts copy timestamps
-shortest finish encoding within shortest input
-b_strategy strategy dynamic b frame selection strategy
-ps size set packet size in bits
-error rate error rate
-muxrate rate set mux rate
-packetsize size set packet size
-muxdelay seconds set the maximum demux-decode delay
-muxpreload seconds set the initial demux-decode delay
AVCodecContext AVOptions:
-bit_rate E.VA.
-bit_rate_tolerance E.V..
-flags EDVA.
-mv4 E.V.. use four motion vector by macroblock (mpeg4)
-obmc E.V.. use overlapped block motion compensation (h263+)
-qpel E.V.. use 1/4 pel motion compensation
-loop E.V.. use loop filter
-gmc E.V.. use gmc
-mv0 E.V.. always try a mb with mv=<0,0>
-part E.V.. use data partitioning
-gray EDV.. only decode/encode grayscale
-psnr E.V.. error[?] variables will be set during encoding
-naq E.V.. normalize adaptive quantization
-ildct E.V.. use interlaced dct
-low_delay .DV.. force low delay
-alt E.V.. enable alternate scantable (mpeg2/mpeg4)
-trell E.V.. use trellis quantization
-bitexact EDVAS use only bitexact stuff (except (i)dct)
-aic E.V.. h263 advanced intra coding / mpeg4 ac prediction
-umv E.V.. use unlimited motion vectors
-cbp E.V.. use rate distortion optimization for cbp
-qprd E.V.. use rate distortion optimization for qp selection
-aiv E.V.. h263 alternative inter vlc
-slice E.V..
-ilme E.V.. interlaced motion estimation
-scan_offset E.V.. will reserve space for svcd scan offset user data
-cgop E.V.. closed gop
-fast E.V.. allow non spec compliant speedup tricks
-sgop E.V.. strictly enforce gop size
-noout E.V.. skip bitstream encoding
-local_header E.V.. place global headers at every keyframe instead of in ex
tradata
-me_method E.V..
-gop_size E.V..
-qcompress E.V..
-qblur E.V..
-qmin E.V..
-qmax E.V..
-max_qdiff E.V..
-max_b_frames E.V..
-b_quant_factor E.V..
-rc_strategy E.V..
-b_frame_strategy E.V..
-hurry_up .DV..
-bugs .DV..
-autodetect .DV..
-old_msmpeg4 .DV..
-xvid_ilace .DV..
-ump4 .DV..
-no_padding .DV..
-amv .DV..
-ac_vlc .DV..
-qpel_chroma .DV..
-std_qpel .DV..
-qpel_chroma2 .DV..
-direct_blocksize .DV..
-edge .DV..
-hpel_chroma .DV..
-dc_clip .DV..
-ms .DV..
-lelim E.V.. single coefficient elimination threshold for luminance
(negative values also consider dc coefficient)
-celim E.V.. single coefficient elimination threshold for chrominanc
e (negative values also consider dc coefficient)
-strict E.V..
-very E.V..
-strict E.V..
-normal E.V..
-inofficial E.V..
-experimental E.V..
-b_quant_offset E.V..
-er .DV..
-careful .DV..
-compliant .DV..
-aggressive .DV..
-very_aggressive .DV..
-mpeg_quant E.V..
-rc_qsquish E.V..
-rc_qmod_amp E.V..
-rc_qmod_freq E.V..
-rc_eq E.V..
-rc_max_rate E.V..
-rc_min_rate E.V..
-rc_buffer_size E.V..
-rc_buf_aggressivity E.V..
-i_quant_factor E.V..
-i_quant_offset E.V..
-rc_initial_cplx E.V..
-dct E.V..
-auto E.V..
-fastint E.V..
-int E.V..
-mmx E.V..
-mlib E.V..
-altivec E.V..
-faan E.V..
-lumi_mask E.V.. lumimasking
-tcplx_mask E.V.. temporal complexity masking
-scplx_mask E.V.. spatial complexity masking
-p_mask E.V.. inter masking
-dark_mask E.V.. darkness masking
-idct EDV..
-auto EDV..
-int EDV..
-simple EDV..
-simplemmx EDV..
-libmpeg2mmx EDV..
-ps2 EDV..
-mlib EDV..
-arm EDV..
-altivec EDV..
-sh4 EDV..
-simplearm EDV..
-h264 EDV..
-vp3 EDV..
-ipp EDV..
-xvidmmx EDV..
-ec .DV..
-guess_mvs .DV..
-deblock .DV..
-pred E.V.. prediction method
-left E.V..
-plane E.V..
-median E.V..
-aspect E.V..
-debug EDVAS print specific debug info
-pict .DV..
-rc E.V..
-bitstream .DV..
-mb_type .DV..
-qp .DV..
-mv .DV..
-dct_coeff .DV..
-skip .DV..
-startcode .DV..
-pts .DV..
-er .DV..
-mmco .DV..
-bugs .DV..
-vis_qp .DV..
-vis_mb_type .DV..
-vismv .DV.. visualize motion vectors
-pf .DV..
-bf .DV..
-bb .DV..
-mb_qmin E.V..
-mb_qmax E.V..
-cmp E.V.. full pel me compare function
-subcmp E.V.. sub pel me compare function
-mbcmp E.V.. macroblock compare function
-ildctcmp E.V.. interlaced dct compare function
-dia_size E.V..
-last_pred E.V..
-preme E.V..
-precmp E.V.. pre motion estimation compare function
-sad E.V..
-sse E.V..
-satd E.V..
-dct E.V..
-psnr E.V..
-bit E.V..
-rd E.V..
-zero E.V..
-vsad E.V..
-vsse E.V..
-nsse E.V..
-w53 E.V..
-w97 E.V..
-dctmax E.V..
-chroma E.V..
-pre_dia_size E.V..
-subq E.V.. sub pel motion estimation quality
-me_range E.V..
-ibias E.V..
-pbias E.V..
-coder E.V..
-vlc E.V.. variable length coder / huffman coder
-ac E.V.. arithmetic coder
-context E.V.. context model
-mbd E.V..
-simple E.V..
-bits E.V..
-rd E.V..
-sc_threshold E.V..
-lmin E.V.. min lagrange factor
-lmax E.V.. max lagrange factor
-nr E.V.. noise reduction
-rc_init_occupancy E.V..
-inter_threshold E.V..
-antialias .DV..
-auto .DV..
-fastint .DV..
-int .DV..
-float .DV..
-qns E.V.. quantizer noise shaping
-thread_count EDV..
-dc E.V..
-nssew E.V.. nsse weight
-skip_top .DV..
-skip_bottom .DV..
-profile E.VA.
-unknown E.VA.
-level E.VA.
-unknown E.VA.
-lowres .DV..
-frame_skip_threshold E.V..
-frame_skip_factor E.V..
-frame_skip_exp E.V..
-skipcmp E.V.. frame skip compare function
-border_mask E.V..
-mb_lmin E.V..
-mb_lmax E.V..
-me_penalty_compensation E.V..
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