使用ffmpeg进行视频转码，剪切，合并与调速
视频转码
视频转码最简单的命令就是
ffmpeg -i ${infile} -vcodec ${outcodec} ${outfile}
其中 -vcodec 后面是编码格式,可以用 ffmpeg -codecs 来查看
ffmpeg -codecs
Codecs: D..... = Decoding supported .E.... = Encoding supported ..V... = Video codec ..A... = Audio codec ..S... = Subtitle codec ...I.. = Intra frame-only codec ....L. = Lossy compression .....S = Lossless compression ------- D.VI.S 012v Uncompressed 4:2:2 10-bit D.V.L. 4xm 4X Movie D.VI.S 8bps QuickTime 8BPS video .EVIL. a64_multi Multicolor charset for Commodore 64 (encoders: a64multi ) .EVIL. a64_multi5 Multicolor charset for Commodore 64, extended with 5th color (colram) (encoders: a64multi5 ) D.V..S aasc Autodesk RLE D.VIL. aic Apple Intermediate Codec DEVI.S alias_pix Alias/Wavefront PIX image DEVIL. amv AMV Video D.V.L. anm Deluxe Paint Animation D.V.L. ansi ASCII/ANSI art DEV..S apng APNG (Animated Portable Network Graphics) image DEVIL. asv1 ASUS V1 DEVIL. asv2 ASUS V2 D.VIL. aura Auravision AURA D.VIL. aura2 Auravision Aura 2 ..V.L. av1 Alliance for Open Media AV1 D.V... avrn Avid AVI Codec DEVI.S avrp Avid 1:1 10-bit RGB Packer D.V.L. avs AVS (Audio Video Standard) video DEVI.S avui Avid Meridien Uncompressed DEVI.S ayuv Uncompressed packed MS 4:4:4:4 D.V.L. bethsoftvid Bethesda VID video D.V.L. bfi Brute Force & Ignorance D.V.L. binkvideo Bink video D.VI.. bintext Binary text D.VI.S bitpacked Bitpacked DEVI.S bmp BMP (Windows and OS/2 bitmap) D.V..S bmv_video Discworld II BMV video D.VI.S brender_pix BRender PIX image D.V.L. c93 Interplay C93 D.V.L. cavs Chinese AVS (Audio Video Standard) (AVS1-P2, JiZhun profile) D.V.L. cdgraphics CD Graphics video D.VIL. cdxl Commodore CDXL video D.V.L. cfhd Cineform HD DEV.L. cinepak Cinepak D.V.L. clearvideo Iterated Systems ClearVideo DEVIL. cljr Cirrus Logic AccuPak D.VI.S cllc Canopus Lossless Codec D.V.L. cmv Electronic Arts CMV video (decoders: eacmv ) D.V... cpia CPiA video format D.V..S cscd CamStudio (decoders: camstudio ) D.VIL. cyuv Creative YUV (CYUV) ..V.LS daala Daala D.VILS dds DirectDraw Surface image decoder D.V.L. dfa Chronomaster DFA DEV.LS dirac Dirac (encoders: vc2 ) DEVIL. dnxhd VC3/DNxHD DEVI.S dpx DPX (Digital Picture Exchange) image D.V.L. dsicinvideo Delphine Software International CIN video DEVIL. dvvideo DV (Digital Video) D.V..S dxa Feeble Files/ScummVM DXA D.VI.S dxtory Dxtory D.VIL. dxv Resolume DXV D.V.L. escape124 Escape 124 D.V.L. escape130 Escape 130 D.VILS exr OpenEXR image DEV..S ffv1 FFmpeg video codec #1 DEVI.S ffvhuff Huffyuv FFmpeg variant D.V.L. fic Mirillis FIC DEVI.S fits FITS (Flexible Image Transport System) DEV..S flashsv Flash Screen Video v1 DEV.L. flashsv2 Flash Screen Video v2 D.V..S flic Autodesk Animator Flic video DEV.L. flv1 FLV / Sorenson Spark / Sorenson H.263 (Flash Video) (decoders: flv ) (encoders: flv ) D.V..S fmvc FM Screen Capture Codec D.VI.S fraps Fraps D.VI.S frwu Forward Uncompressed D.V.L. g2m Go2Meeting D.V.L. gdv Gremlin Digital Video DEV..S gif GIF (Graphics Interchange Format) DEV.L. h261 H.261 DEV.L. h263 H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 (decoders: h263 h263_v4l2m2m ) (encoders: h263 h263_v4l2m2m ) D.V.L. h263i Intel H.263 DEV.L. h263p H.263+ / H.263-1998 / H.263 version 2 DEV.LS h264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_v4l2m2m h264_cuvid ) (encoders: libx264 libx264rgb h264_nvenc h264_omx h264_v4l2m2m h264_vaapi nvenc nvenc_h264 ) D.VIL. hap Vidvox Hap DEV.L. hevc H.265 / HEVC (High Efficiency Video Coding) (decoders: hevc hevc_cuvid ) (encoders: libx265 nvenc_hevc hevc_nvenc hevc_vaapi ) D.V.L. hnm4video HNM 4 video D.VIL. hq_hqa Canopus HQ/HQA D.VIL. hqx Canopus HQX DEVI.S huffyuv HuffYUV D.V.L. idcin id Quake II CIN video (decoders: idcinvideo ) D.VI.. idf iCEDraw text D.V.L. iff_ilbm IFF ACBM/ANIM/DEEP/ILBM/PBM/RGB8/RGBN (decoders: iff ) D.V.L. indeo2 Intel Indeo 2 D.V.L. indeo3 Intel Indeo 3 D.V.L. indeo4 Intel Indeo Video Interactive 4 D.V.L. indeo5 Intel Indeo Video Interactive 5 D.V.L. interplayvideo Interplay MVE video DEVILS jpeg2000 JPEG 2000 (decoders: jpeg2000 libopenjpeg ) (encoders: jpeg2000 libopenjpeg ) DEVILS jpegls JPEG-LS D.VIL. jv Bitmap Brothers JV video D.V.L. kgv1 Kega Game Video D.V.L. kmvc Karl Morton's video codec D.VI.S lagarith Lagarith lossless .EVI.S ljpeg Lossless JPEG D.VI.S loco LOCO D.VI.S m101 Matrox Uncompressed SD D.V.L. mad Electronic Arts Madcow Video (decoders: eamad ) DEVI.S magicyuv MagicYUV video D.VIL. mdec Sony PlayStation MDEC (Motion DECoder) D.V.L. mimic Mimic DEVIL. mjpeg Motion JPEG (decoders: mjpeg mjpeg_cuvid ) (encoders: mjpeg mjpeg_vaapi ) D.VIL. mjpegb Apple MJPEG-B D.V.L. mmvideo American Laser Games MM Video D.V.L. motionpixels Motion Pixels video DEV.L. mpeg1video MPEG-1 video (decoders: mpeg1video mpeg1_v4l2m2m mpeg1_cuvid ) DEV.L. mpeg2video MPEG-2 video (decoders: mpeg2video mpegvideo mpeg2_v4l2m2m mpeg2_cuvid ) (encoders: mpeg2video mpeg2_vaapi ) DEV.L. mpeg4 MPEG-4 part 2 (decoders: mpeg4 mpeg4_v4l2m2m mpeg4_cuvid ) (encoders: mpeg4 libxvid mpeg4_v4l2m2m ) D.V.L. msa1 MS ATC Screen D.VI.S mscc Mandsoft Screen Capture Codec D.V.L. msmpeg4v1 MPEG-4 part 2 Microsoft variant version 1 DEV.L. msmpeg4v2 MPEG-4 part 2 Microsoft variant version 2 DEV.L. msmpeg4v3 MPEG-4 part 2 Microsoft variant version 3 (decoders: msmpeg4 ) (encoders: msmpeg4 ) D.V..S msrle Microsoft RLE D.V.L. mss1 MS Screen 1 D.VIL. mss2 MS Windows Media Video V9 Screen DEV.L. msvideo1 Microsoft Video 1 D.VI.S mszh LCL (LossLess Codec Library) MSZH D.V.L. mts2 MS Expression Encoder Screen D.VIL. mvc1 Silicon Graphics Motion Video Compressor 1 D.VIL. mvc2 Silicon Graphics Motion Video Compressor 2 D.V.L. mxpeg Mobotix MxPEG video D.V.L. nuv NuppelVideo/RTJPEG D.V.L. paf_video Amazing Studio Packed Animation File Video DEVI.S pam PAM (Portable AnyMap) image DEVI.S pbm PBM (Portable BitMap) image DEVI.S pcx PC Paintbrush PCX image DEVI.S pgm PGM (Portable GrayMap) image DEVI.S pgmyuv PGMYUV (Portable GrayMap YUV) image D.VIL. pictor Pictor/PC Paint D.VIL. pixlet Apple Pixlet DEV..S png PNG (Portable Network Graphics) image DEVI.S ppm PPM (Portable PixelMap) image DEVIL. prores Apple ProRes (iCodec Pro) (decoders: prores prores_lgpl ) (encoders: prores prores_aw prores_ks ) D.VI.S psd Photoshop PSD file D.VIL. ptx V.Flash PTX image D.VI.S qdraw Apple QuickDraw D.V.L. qpeg Q-team QPEG DEV..S qtrle QuickTime Animation (RLE) video DEVI.S r10k AJA Kona 10-bit RGB Codec DEVI.S r210 Uncompressed RGB 10-bit DEVI.S rawvideo raw video D.VIL. rl2 RL2 video DEV.L. roq id RoQ video (decoders: roqvideo ) (encoders: roqvideo ) D.V.L. rpza QuickTime video (RPZA) D.V..S rscc innoHeim/Rsupport Screen Capture Codec DEV.L. rv10 RealVideo 1.0 DEV.L. rv20 RealVideo 2.0 D.V.L. rv30 RealVideo 3.0 D.V.L. rv40 RealVideo 4.0 D.V.L. sanm LucasArts SANM/SMUSH video D.V.LS scpr ScreenPressor D.V..S screenpresso Screenpresso DEVI.S sgi SGI image D.VI.S sgirle SGI RLE 8-bit D.VI.S sheervideo BitJazz SheerVideo D.V.L. smackvideo Smacker video (decoders: smackvid ) D.V.L. smc QuickTime Graphics (SMC) D.V... smvjpeg Sigmatel Motion Video DEV.LS snow Snow D.VIL. sp5x Sunplus JPEG (SP5X) D.VIL. speedhq NewTek SpeedHQ D.VI.S srgc Screen Recorder Gold Codec DEVI.S sunrast Sun Rasterfile image ..V..S svg Scalable Vector Graphics DEV.L. svq1 Sorenson Vector Quantizer 1 / Sorenson Video 1 / SVQ1 D.V.L. svq3 Sorenson Vector Quantizer 3 / Sorenson Video 3 / SVQ3 DEVI.S targa Truevision Targa image D.VI.S targa_y216 Pinnacle TARGA CineWave YUV16 D.V.L. tdsc TDSC D.V.L. tgq Electronic Arts TGQ video (decoders: eatgq ) D.V.L. tgv Electronic Arts TGV video (decoders: eatgv ) DEV.L. theora Theora (encoders: libtheora ) D.VIL. thp Nintendo Gamecube THP video D.V.L. tiertexseqvideo Tiertex Limited SEQ video DEVI.S tiff TIFF image D.VIL. tmv 8088flex TMV D.V.L. tqi Electronic Arts TQI video (decoders: eatqi ) D.V.L. truemotion1 Duck TrueMotion 1.0 D.V.L. truemotion2 Duck TrueMotion 2.0 D.V.L. truemotion2rt Duck TrueMotion 2.0 Real Time D.V..S tscc TechSmith Screen Capture Codec (decoders: camtasia ) D.V.L. tscc2 TechSmith Screen Codec 2 D.VIL. txd Renderware TXD (TeXture Dictionary) image D.V.L. ulti IBM UltiMotion (decoders: ultimotion ) DEVI.S utvideo Ut Video DEVI.S v210 Uncompressed 4:2:2 10-bit D.VI.S v210x Uncompressed 4:2:2 10-bit DEVI.S v308 Uncompressed packed 4:4:4 DEVI.S v408 Uncompressed packed QT 4:4:4:4 DEVI.S v410 Uncompressed 4:4:4 10-bit D.V.L. vb Beam Software VB D.VI.S vble VBLE Lossless Codec D.V.L. vc1 SMPTE VC-1 (decoders: vc1 vc1_v4l2m2m vc1_cuvid ) D.V.L. vc1image Windows Media Video 9 Image v2 D.VIL. vcr1 ATI VCR1 D.VIL. vixl Miro VideoXL (decoders: xl ) D.V.L. vmdvideo Sierra VMD video D.V..S vmnc VMware Screen Codec / VMware Video D.V.L. vp3 On2 VP3 D.V.L. vp5 On2 VP5 D.V.L. vp6 On2 VP6 D.V.L. vp6a On2 VP6 (Flash version, with alpha channel) D.V.L. vp6f On2 VP6 (Flash version) D.V.L. vp7 On2 VP7 DEV.L. vp8 On2 VP8 (decoders: vp8 vp8_v4l2m2m libvpx vp8_cuvid ) (encoders: libvpx vp8_v4l2m2m vp8_vaapi ) DEV.L. vp9 Google VP9 (decoders: vp9 vp9_v4l2m2m libvpx-vp9 vp9_cuvid ) (encoders: libvpx-vp9 vp9_vaapi ) DEVILS webp WebP (encoders: libwebp_anim libwebp ) DEV.L. wmv1 Windows Media Video 7 DEV.L. wmv2 Windows Media Video 8 D.V.L. wmv3 Windows Media Video 9 D.V.L. wmv3image Windows Media Video 9 Image D.VIL. wnv1 Winnov WNV1 DEV..S wrapped_avframe AVFrame to AVPacket passthrough D.V.L. ws_vqa Westwood Studios VQA (Vector Quantized Animation) video (decoders: vqavideo ) D.V.L. xan_wc3 Wing Commander III / Xan D.V.L. xan_wc4 Wing Commander IV / Xxan D.VI.. xbin eXtended BINary text DEVI.S xbm XBM (X BitMap) image DEVIL. xface X-face image D.VI.S xpm XPM (X PixMap) image DEVI.S xwd XWD (X Window Dump) image DEVI.S y41p Uncompressed YUV 4:1:1 12-bit D.VI.S ylc YUY2 Lossless Codec D.V.L. yop Psygnosis YOP Video DEVI.S yuv4 Uncompressed packed 4:2:0 D.V..S zerocodec ZeroCodec Lossless Video DEVI.S zlib LCL (LossLess Codec Library) ZLIB DEV..S zmbv Zip Motion Blocks Video ..A.L. 4gv 4GV (Fourth Generation Vocoder) D.A.L. 8svx_exp 8SVX exponential D.A.L. 8svx_fib 8SVX fibonacci DEA.L. aac AAC (Advanced Audio Coding) (decoders: aac aac_fixed ) D.A.L. aac_latm AAC LATM (Advanced Audio Coding LATM syntax) DEA.L. ac3 ATSC A/52A (AC-3) (decoders: ac3 ac3_fixed ) (encoders: ac3 ac3_fixed ) D.A.L. adpcm_4xm ADPCM 4X Movie DEA.L. adpcm_adx SEGA CRI ADX ADPCM D.A.L. adpcm_afc ADPCM Nintendo Gamecube AFC D.A.L. adpcm_aica ADPCM Yamaha AICA D.A.L. adpcm_ct ADPCM Creative Technology D.A.L. adpcm_dtk ADPCM Nintendo Gamecube DTK D.A.L. adpcm_ea ADPCM Electronic Arts D.A.L. adpcm_ea_maxis_xa ADPCM Electronic Arts Maxis CDROM XA D.A.L. adpcm_ea_r1 ADPCM Electronic Arts R1 D.A.L. adpcm_ea_r2 ADPCM Electronic Arts R2 D.A.L. adpcm_ea_r3 ADPCM Electronic Arts R3 D.A.L. adpcm_ea_xas ADPCM Electronic Arts XAS DEA.L. adpcm_g722 G.722 ADPCM (decoders: g722 ) (encoders: g722 ) DEA.L. adpcm_g726 G.726 ADPCM (decoders: g726 ) (encoders: g726 ) DEA.L. adpcm_g726le G.726 ADPCM little-endian (decoders: g726le ) (encoders: g726le ) D.A.L. adpcm_ima_amv ADPCM IMA AMV D.A.L. adpcm_ima_apc ADPCM IMA CRYO APC D.A.L. adpcm_ima_dat4 ADPCM IMA Eurocom DAT4 D.A.L. adpcm_ima_dk3 ADPCM IMA Duck DK3 D.A.L. adpcm_ima_dk4 ADPCM IMA Duck DK4 D.A.L. adpcm_ima_ea_eacs ADPCM IMA Electronic Arts EACS D.A.L. adpcm_ima_ea_sead ADPCM IMA Electronic Arts SEAD D.A.L. adpcm_ima_iss ADPCM IMA Funcom ISS D.A.L. adpcm_ima_oki ADPCM IMA Dialogic OKI DEA.L. adpcm_ima_qt ADPCM IMA QuickTime D.A.L. adpcm_ima_rad ADPCM IMA Radical D.A.L. adpcm_ima_smjpeg ADPCM IMA Loki SDL MJPEG DEA.L. adpcm_ima_wav ADPCM IMA WAV D.A.L. adpcm_ima_ws ADPCM IMA Westwood DEA.L. adpcm_ms ADPCM Microsoft D.A.L. adpcm_mtaf ADPCM MTAF D.A.L. adpcm_psx ADPCM Playstation D.A.L. adpcm_sbpro_2 ADPCM Sound Blaster Pro 2-bit D.A.L. adpcm_sbpro_3 ADPCM Sound Blaster Pro 2.6-bit D.A.L. adpcm_sbpro_4 ADPCM Sound Blaster Pro 4-bit DEA.L. adpcm_swf ADPCM Shockwave Flash D.A.L. adpcm_thp ADPCM Nintendo THP D.A.L. adpcm_thp_le ADPCM Nintendo THP (Little-Endian) D.A.L. adpcm_vima LucasArts VIMA audio D.A.L. adpcm_xa ADPCM CDROM XA DEA.L. adpcm_yamaha ADPCM Yamaha DEAI.S alac ALAC (Apple Lossless Audio Codec) DEA.L. amr_nb AMR-NB (Adaptive Multi-Rate NarrowBand) (decoders: amrnb libopencore_amrnb ) (encoders: libopencore_amrnb ) D.A.L. amr_wb AMR-WB (Adaptive Multi-Rate WideBand) (decoders: amrwb libopencore_amrwb ) D.A..S ape Monkey's Audio DEA.L. aptx aptX (Audio Processing Technology for Bluetooth) DEA.L. aptx_hd aptX HD (Audio Processing Technology for Bluetooth) D.A.L. atrac1 ATRAC1 (Adaptive TRansform Acoustic Coding) D.A.L. atrac3 ATRAC3 (Adaptive TRansform Acoustic Coding 3) D.A..S atrac3al ATRAC3 AL (Adaptive TRansform Acoustic Coding 3 Advanced Lossless) D.A.L. atrac3p ATRAC3+ (Adaptive TRansform Acoustic Coding 3+) (decoders: atrac3plus ) D.A..S atrac3pal ATRAC3+ AL (Adaptive TRansform Acoustic Coding 3+ Advanced Lossless) (decoders: atrac3plusal ) D.A.L. avc On2 Audio for Video Codec (decoders: on2avc ) D.A.L. binkaudio_dct Bink Audio (DCT) D.A.L. binkaudio_rdft Bink Audio (RDFT) D.A.L. bmv_audio Discworld II BMV audio ..A.L. celt Constrained Energy Lapped Transform (CELT) ..A.L. codec2 codec2 (very low bitrate speech codec) DEA.L. comfortnoise RFC 3389 Comfort Noise D.A.L. cook Cook / Cooker / Gecko (RealAudio G2) D.A.L. dolby_e Dolby E D.A.L. dsd_lsbf DSD (Direct Stream Digital), least significant bit first D.A.L. dsd_lsbf_planar DSD (Direct Stream Digital), least significant bit first, planar D.A.L. dsd_msbf DSD (Direct Stream Digital), most significant bit first D.A.L. dsd_msbf_planar DSD (Direct Stream Digital), most significant bit first, planar D.A.L. dsicinaudio Delphine Software International CIN audio D.A.L. dss_sp Digital Speech Standard - Standard Play mode (DSS SP) D.A..S dst DST (Direct Stream Transfer) DEA.LS dts DCA (DTS Coherent Acoustics) (decoders: dca ) (encoders: dca ) D.A.L. dvaudio DV audio DEA.L. eac3 ATSC A/52B (AC-3, E-AC-3) D.A.L. evrc EVRC (Enhanced Variable Rate Codec) DEAI.S flac FLAC (Free Lossless Audio Codec) DEA.L. g723_1 G.723.1 D.A.L. g729 G.729 D.A.L. gremlin_dpcm DPCM Gremlin DEA.L. gsm GSM (decoders: gsm libgsm ) (encoders: libgsm ) DEA.L. gsm_ms GSM Microsoft variant (decoders: gsm_ms libgsm_ms ) (encoders: libgsm_ms ) D.A.L. iac IAC (Indeo Audio Coder) ..A.L. ilbc iLBC (Internet Low Bitrate Codec) D.A.L. imc IMC (Intel Music Coder) D.A.L. interplay_dpcm DPCM Interplay D.A.L. interplayacm Interplay ACM D.A.L. mace3 MACE (Macintosh Audio Compression/Expansion) 3:1 D.A.L. mace6 MACE (Macintosh Audio Compression/Expansion) 6:1 D.A.L. metasound Voxware MetaSound DEA..S mlp MLP (Meridian Lossless Packing) D.A.L. mp1 MP1 (MPEG audio layer 1) (decoders: mp1 mp1float ) DEA.L. mp2 MP2 (MPEG audio layer 2) (decoders: mp2 mp2float ) (encoders: mp2 mp2fixed ) DEA.L. mp3 MP3 (MPEG audio layer 3) (decoders: mp3float mp3 ) (encoders: libmp3lame ) D.A.L. mp3adu ADU (Application Data Unit) MP3 (MPEG audio layer 3) (decoders: mp3adufloat mp3adu ) D.A.L. mp3on4 MP3onMP4 (decoders: mp3on4float mp3on4 ) D.A..S mp4als MPEG-4 Audio Lossless Coding (ALS) (decoders: als ) D.A.L. musepack7 Musepack SV7 (decoders: mpc7 ) D.A.L. musepack8 Musepack SV8 (decoders: mpc8 ) DEA.L. nellymoser Nellymoser Asao DEA.L. opus Opus (Opus Interactive Audio Codec) (decoders: opus libopus ) (encoders: opus libopus ) D.A.L. paf_audio Amazing Studio Packed Animation File Audio DEA.L. pcm_alaw PCM A-law / G.711 A-law D.A..S pcm_bluray PCM signed 16|20|24-bit big-endian for Blu-ray media D.A..S pcm_dvd PCM signed 20|24-bit big-endian D.A..S pcm_f16le PCM 16.8 floating point little-endian D.A..S pcm_f24le PCM 24.0 floating point little-endian DEA..S pcm_f32be PCM 32-bit floating point big-endian DEA..S pcm_f32le PCM 32-bit floating point little-endian DEA..S pcm_f64be PCM 64-bit floating point big-endian DEA..S pcm_f64le PCM 64-bit floating point little-endian D.A..S pcm_lxf PCM signed 20-bit little-endian planar DEA.L. pcm_mulaw PCM mu-law / G.711 mu-law DEA..S pcm_s16be PCM signed 16-bit big-endian DEA..S pcm_s16be_planar PCM signed 16-bit big-endian planar DEA..S pcm_s16le PCM signed 16-bit little-endian DEA..S pcm_s16le_planar PCM signed 16-bit little-endian planar DEA..S pcm_s24be PCM signed 24-bit big-endian DEA..S pcm_s24daud PCM D-Cinema audio signed 24-bit DEA..S pcm_s24le PCM signed 24-bit little-endian DEA..S pcm_s24le_planar PCM signed 24-bit little-endian planar DEA..S pcm_s32be PCM signed 32-bit big-endian DEA..S pcm_s32le PCM signed 32-bit little-endian DEA..S pcm_s32le_planar PCM signed 32-bit little-endian planar DEA..S pcm_s64be PCM signed 64-bit big-endian DEA..S pcm_s64le PCM signed 64-bit little-endian DEA..S pcm_s8 PCM signed 8-bit DEA..S pcm_s8_planar PCM signed 8-bit planar DEA..S pcm_u16be PCM unsigned 16-bit big-endian DEA..S pcm_u16le PCM unsigned 16-bit little-endian DEA..S pcm_u24be PCM unsigned 24-bit big-endian DEA..S pcm_u24le PCM unsigned 24-bit little-endian DEA..S pcm_u32be PCM unsigned 32-bit big-endian DEA..S pcm_u32le PCM unsigned 32-bit little-endian DEA..S pcm_u8 PCM unsigned 8-bit D.A.L. pcm_zork PCM Zork D.A.L. qcelp QCELP / PureVoice D.A.L. qdm2 QDesign Music Codec 2 D.A.L. qdmc QDesign Music DEA.L. ra_144 RealAudio 1.0 (14.4K) (decoders: real_144 ) (encoders: real_144 ) D.A.L. ra_288 RealAudio 2.0 (28.8K) (decoders: real_288 ) D.A..S ralf RealAudio Lossless DEA.L. roq_dpcm DPCM id RoQ DEA..S s302m SMPTE 302M DEA.L. sbc SBC (low-complexity subband codec) D.A.L. sdx2_dpcm DPCM Squareroot-Delta-Exact D.A..S shorten Shorten D.A.L. sipr RealAudio SIPR / ACELP.NET D.A.L. smackaudio Smacker audio (decoders: smackaud ) ..A.L. smv SMV (Selectable Mode Vocoder) D.A.L. sol_dpcm DPCM Sol DEA... sonic Sonic .EA... sonicls Sonic lossless DEA.L. speex Speex (decoders: libspeex ) (encoders: libspeex ) D.AI.S tak TAK (Tom's lossless Audio Kompressor) DEA..S truehd TrueHD D.A.L. truespeech DSP Group TrueSpeech DEAI.S tta TTA (True Audio) D.A.L. twinvq VQF TwinVQ D.A.L. vmdaudio Sierra VMD audio DEA.L. vorbis Vorbis (decoders: vorbis libvorbis ) (encoders: vorbis libvorbis ) D.A... wavesynth Wave synthesis pseudo-codec DEAILS wavpack WavPack D.A.L. westwood_snd1 Westwood Audio (SND1) (decoders: ws_snd1 ) D.A..S wmalossless Windows Media Audio Lossless D.A.L. wmapro Windows Media Audio 9 Professional DEA.L. wmav1 Windows Media Audio 1 DEA.L. wmav2 Windows Media Audio 2 D.A.L. wmavoice Windows Media Audio Voice D.A.L. xan_dpcm DPCM Xan D.A.L. xma1 Xbox Media Audio 1 D.A.L. xma2 Xbox Media Audio 2 ..D... bin_data binary data ..D... dvd_nav_packet DVD Nav packet ..D... klv SMPTE 336M Key-Length-Value (KLV) metadata ..D... otf OpenType font ..D... scte_35 SCTE 35 Message Queue ..D... timed_id3 timed ID3 metadata ..D... ttf TrueType font DES... ass ASS (Advanced SSA) subtitle (decoders: ssa ass ) (encoders: ssa ass ) DES... dvb_subtitle DVB subtitles (decoders: dvbsub ) (encoders: dvbsub ) ..S... dvb_teletext DVB teletext DES... dvd_subtitle DVD subtitles (decoders: dvdsub ) (encoders: dvdsub ) D.S... eia_608 EIA-608 closed captions (decoders: cc_dec ) D.S... hdmv_pgs_subtitle HDMV Presentation Graphic Stream subtitles (decoders: pgssub ) ..S... hdmv_text_subtitle HDMV Text subtitle D.S... jacosub JACOsub subtitle D.S... microdvd MicroDVD subtitle DES... mov_text MOV text D.S... mpl2 MPL2 subtitle D.S... pjs PJS (Phoenix Japanimation Society) subtitle D.S... realtext RealText subtitle D.S... sami SAMI subtitle ..S... srt SubRip subtitle with embedded timing ..S... ssa SSA (SubStation Alpha) subtitle D.S... stl Spruce subtitle format DES... subrip SubRip subtitle (decoders: srt subrip ) (encoders: srt subrip ) D.S... subviewer SubViewer subtitle D.S... subviewer1 SubViewer v1 subtitle DES... text raw UTF-8 text D.S... vplayer VPlayer subtitle DES... webvtt WebVTT subtitle DES... xsub XSUB
注意第三行 .E.... = Encoding supported,说明带有 E 标志的才是支持转出的编码格式.
我们也可以通过一些附加选项指定转换规则：
- -r
- 指定帧率
- -s
- 指定分辨率
- -b
- 指定比特率；于此同时可以对声道进行转码
- -acodec
- 指定音频编码
- -ab
- 指定音频比特率
- -ac
- 指定声道数
比如：
ffmpeg -i 01.mp4 -s 640x480 -b:v 500k -vcodec h264 -r 29.97 -ab 48k -ac 2 out.mp4
视频剪切
视频剪切可以认为是一种特殊的视频转换过程，不过它不需要经过decode再encode的过程，而是可以直接进行流拷贝。
使用ffmpeg进行流拷贝可以通过 -c copy 参数来进行。
既然是视频剪切当然就需要指定剪切的开始位置和结束位置了，可以使用 -ss 参数指定开始位置，使用 -t 参数指定截取时间长度,或者使用 -to 参数指定截取的结束位置
比如下面命令截取从30秒开始，持续10秒钟的内容
ffmpeg -i input.wmv -ss 00:00:30.0 -c copy -t 10 output.wmv
视频合并
视频合并要求被合并的文件格式是一样的，否则需要先将它们转换成统一的中间格式。
然后将将所有要合并的视频，每个视频一行，将视频文件的路径存在一个列表文件中，然后执行
ffmpeg -f concat -i ${listfile} -c copy ${outfile}
视频调速
通过设置video filter来实现,比如
加速四倍：
ffmpeg -i TheOrigin.mp4 -vf "setpts=0.25*PTS" UpTheOrigin.mp4
四倍慢速：
ffmpeg -i TheOrigin.mp4 -vf "setpts=4*PTS" DownTheOrigin.mp4
