ffmpeg转板卡可以播放的alaw

将amr转为语音板卡可以播放的alaw编码的wav文件

ffmpeg -i YY20121129_023829.amr   -acodec  pcm_alaw   yuyin2.wav

其他可用编码器

用命令查看 

 ffmpeg -encoders

 V..... a64multi             Multicolor charset for Commodore 64 (codec a64_multi)
 V..... a64multi5            Multicolor charset for Commodore 64, extended with 5th color (colram) (codec a64_multi5)
 V..... amv                  AMV Video
 V..... asv1                 ASUS V1
 V..... asv2                 ASUS V2
 V..... avrp                 Avid 1:1 10-bit RGB Packer
 V..X.. avui                 Avid Meridien Uncompressed
 V..... ayuv                 Uncompressed packed MS 4:4:4:4
 V..... bmp                  BMP (Windows and OS/2 bitmap)
 V..... cljr                 Cirrus Logic AccuPak
 V.S... dnxhd                VC3/DNxHD
 V..... dpx                  DPX image
 V.S... dvvideo              DV (Digital Video)
 V.S... ffv1                 FFmpeg video codec #1
 V..... ffvhuff              Huffyuv FFmpeg variant
 V..... flashsv              Flash Screen Video
 V..... flashsv2             Flash Screen Video Version 2
 V..... flv                  FLV / Sorenson Spark / Sorenson H.263 (Flash Video) (codec flv1)
 V..... gif                  GIF (Graphics Interchange Format)
 V..... h261                 H.261
 V..... h263                 H.263 / H.263-1996
 V.S... h263p                H.263+ / H.263-1998 / H.263 version 2
 V..... huffyuv              Huffyuv / HuffYUV
 V..X.. j2k                  JPEG 2000 (codec jpeg2000)
 V..... jpegls               JPEG-LS
 V..... ljpeg                Lossless JPEG
 VFS... mjpeg                MJPEG (Motion JPEG)
 V..... mpeg1video           MPEG-1 video
 V.S... mpeg2video           MPEG-2 video
 V.S... mpeg4                MPEG-4 part 2
 V..... msmpeg4v2            MPEG-4 part 2 Microsoft variant version 2
 V..... msmpeg4              MPEG-4 part 2 Microsoft variant version 3 (codec msmpeg4v3)
 V..... msvideo1             Microsoft Video-1
 V..... pam                  PAM (Portable AnyMap) image
 V..... pbm                  PBM (Portable BitMap) image
 V..... pcx                  PC Paintbrush PCX image
 V..... pgm                  PGM (Portable GrayMap) image
 V..... pgmyuv               PGMYUV (Portable GrayMap YUV) image
 VF.... png                  PNG (Portable Network Graphics) image
 V..... ppm                  PPM (Portable PixelMap) image
 VF.... prores               Apple ProRes
 VF.... prores_anatoliy      Apple ProRes (codec prores)
 V.S... prores_kostya        Apple ProRes (iCodec Pro) (codec prores)
 V..... qtrle                QuickTime Animation (RLE) video
 V..... r10k                 AJA Kona 10-bit RGB Codec
 V..... r210                 Uncompressed RGB 10-bit
 V..... rawvideo             raw video
 V..... roqvideo             id RoQ video (codec roq)
 V..... rv10                 RealVideo 1.0
 V..... rv20                 RealVideo 2.0
 V..... sgi                  SGI image
 V..... snow                 Snow
 V..... sunrast              Sun Rasterfile image
 V..... svq1                 Sorenson Vector Quantizer 1 / Sorenson Video 1 / SVQ1
 V..... targa                Truevision Targa image
 V..... tiff                 TIFF image
 V..... utvideo              Ut Video
 V..... v210                 Uncompressed 4:2:2 10-bit
 V..... v308                 Uncompressed packed 4:4:4
 V..... v408                 Uncompressed packed QT 4:4:4:4
 V..... v410                 Uncompressed 4:4:4 10-bit
 V..... wmv1                 Windows Media Video 7
 V..... wmv2                 Windows Media Video 8
 V..... xbm                  XBM (X BitMap) image
 V..... xwd                  XWD (X Window Dump) image
 V..... y41p                 Uncompressed YUV 4:1:1 12-bit
 V..... yuv4                 Uncompressed packed 4:2:0
 V..... zlib                 LCL (LossLess Codec Library) ZLIB
 V..... zmbv                 Zip Motion Blocks Video
 A..X.. aac                  AAC (Advanced Audio Coding)
 A..... libfaac              libfaac AAC (Advanced Audio Coding) (codec aac)
 A..... ac3                  ATSC A/52A (AC-3)
 A..... ac3_fixed            ATSC A/52A (AC-3) (codec ac3)
 A..... adpcm_adx            SEGA CRI ADX ADPCM
 A..... g722                 G.722 ADPCM (codec adpcm_g722)
 A..... g726                 G.726 ADPCM (codec adpcm_g726)
 A..... adpcm_ima_qt         ADPCM IMA QuickTime
 A..... adpcm_ima_wav        ADPCM IMA WAV
 A..... adpcm_ms             ADPCM Microsoft
 A..... adpcm_swf            ADPCM Shockwave Flash
 A..... adpcm_yamaha         ADPCM Yamaha
 A..... alac                 ALAC (Apple Lossless Audio Codec)
 A..... libopencore_amrnb    OpenCORE AMR-NB (Adaptive Multi-Rate Narrow-Band) (codec amr_nb)
 A..X.. dca                  DCA (DTS Coherent Acoustics) (codec dts)
 A..... eac3                 ATSC A/52 E-AC-3
 A..... flac                 FLAC (Free Lossless Audio Codec)
 A..... g723_1               G.723.1
 A..... mp2                  MP2 (MPEG audio layer 2)
 A..... nellymoser           Nellymoser Asao
 A..... pcm_alaw             PCM A-law / G.711 A-law
 A..... pcm_f32be            PCM 32-bit floating point big-endian
 A..... pcm_f32le            PCM 32-bit floating point little-endian
 A..... pcm_f64be            PCM 64-bit floating point big-endian
 A..... pcm_f64le            PCM 64-bit floating point little-endian
 A..... pcm_mulaw            PCM mu-law / G.711 mu-law
 A..... pcm_s16be            PCM signed 16-bit big-endian
 A..... pcm_s16le            PCM signed 16-bit little-endian
 A..... pcm_s24be            PCM signed 24-bit big-endian
 A..... pcm_s24daud          PCM D-Cinema audio signed 24-bit
 A..... pcm_s24le            PCM signed 24-bit little-endian
 A..... pcm_s32be            PCM signed 32-bit big-endian
 A..... pcm_s32le            PCM signed 32-bit little-endian
 A..... pcm_s8               PCM signed 8-bit
 A..... pcm_u16be            PCM unsigned 16-bit big-endian
 A..... pcm_u16le            PCM unsigned 16-bit little-endian
 A..... pcm_u24be            PCM unsigned 24-bit big-endian
 A..... pcm_u24le            PCM unsigned 24-bit little-endian
 A..... pcm_u32be            PCM unsigned 32-bit big-endian
 A..... pcm_u32le            PCM unsigned 32-bit little-endian
 A..... pcm_u8               PCM unsigned 8-bit
 A..... real_144             RealAudio 1.0 (14.4K) (codec ra_144)
 A..... roq_dpcm             id RoQ DPCM
 A..X.. sonic                Sonic
 A..X.. sonicls              Sonic lossless
 A..X.. vorbis               Vorbis
 A..... wmav1                Windows Media Audio 1
 A..... wmav2                Windows Media Audio 2
 S..... dvbsub               DVB subtitles (codec dvb_subtitle)
 S..... dvdsub               DVD subtitles (codec dvd_subtitle)
 S..... mov_text             3GPP Timed Text subtitle
 S..... srt                  SubRip subtitle with embedded timing
 S..... ass                  SSA (SubStation Alpha) subtitle (codec ssa)
 S..... subrip               SubRip subtitle
 S..... xsub                 DivX subtitles (XSUB)