Tengo un archivo: muestra.mkv
=========================================================
File: sample.mkv
Width: 854 pixels
Height: 480 pixels
Aspect ratio: 1.77:1
Frames: 0
Duration: 00:00:33 hours/mins/secs
Framerate: 25.000 frames per second
Video format: H264
Video bitrate: 0 bits per second
---------------------------
Audio track 1 (Stream 0.1, AID 0):
---------------------------
Codec: pcm_s16le
Bitrate: 4233000 bits per second
Sampling rate: 44100 Hz
=========================================================
Quiero recodificarlo en un contenedor FLV mediante ffmpeg:
$ ffmpeg -i sample.mkv -b:a 4233k -c:v h264 -c:a pcm_s16le sample.flv
pero recibí:
=========================================================
File: sample.flv
Width: 854 pixels
Height: 480 pixels
Aspect ratio: 1.77:1
Frames: 0
Duration: 00:00:33 hours/mins/secs
Framerate: 25.000 frames per second
Video format: H264
Video bitrate: 0 bits per second
---------------------------
Audio track 1 (Stream 0.1, AID 0):
---------------------------
Codec: pcm_s16le
Bitrate: 1411000 bits per second
Sampling rate: 44100 Hz
=========================================================
¿Por qué la tasa de bits es 4233000 -> 1411000?
En este sentido el sonido sale muy mal :(
ACTUALIZAR registro completo
ffmpeg -i sample.mkv -b:a 4233k -c:v h264 -c:a pcm_s16le sample.flv
ffmpeg version 2.6.2 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
configuration: --prefix=/opt/ffmpeg --libdir=/opt/ffmpeg/lib/ --enable-shared --enable-avresample --disable-stripping --enable-gpl --enable-version3 --enable-nonfree --enable-runtime-cpudetect --build-suffix=.ffmpeg --enable-postproc --enable-x11grab --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libdc1394 --enable-libfaac --enable-libfdk_aac --enable-libflite --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libvo-aacenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-openal --enable-opengl --enable-pthreads --enable-vaapi --enable-vdpau --enable-zlib --enable-debug=3
libavutil 54. 20.100 / 54. 20.100
libavcodec 56. 26.100 / 56. 26.100
libavformat 56. 25.101 / 56. 25.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 11.102 / 5. 11.102
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Guessed Channel Layout for Input Stream #0.1 : 5.1
Input #0, matroska,webm, from 'sample.mkv':
Metadata:
MINOR_VERSION : 512
COMPATIBLE_BRANDS: qt
MAJOR_BRAND : qt
ENCODER : Lavf56.25.101
Duration: 00:00:33.08, start: 0.080000, bitrate: 4691 kb/s
Stream #0:0(eng): Video: h264 (High), yuv420p, 854x480 [SAR 1:1 DAR 427:240], 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
ENCODER : Lavc56.26.100 libx264
Stream #0:1(eng): Audio: pcm_s16le, 44100 Hz, 6 channels, s16, 4233 kb/s (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
ENCODER : Lavc56.26.100 pcm_s16le
[libx264 @ 0x914de0] using SAR=1/1
[libx264 @ 0x914de0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0x914de0] profile High, level 3.0
[libx264 @ 0x914de0] 264 - core 142 r2389 956c8d8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - 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=6 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=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
Output #0, flv, to 'sample.flv':
Metadata:
MINOR_VERSION : 512
COMPATIBLE_BRANDS: qt
MAJOR_BRAND : qt
encoder : Lavf56.25.101
Stream #0:0(eng): Video: h264 (libx264) ([7][0][0][0] / 0x0007), yuv420p, 854x480 [SAR 1:1 DAR 427:240], q=-1--1, 25 fps, 1k tbn, 25 tbc (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
encoder : Lavc56.26.100 libx264
Stream #0:1(eng): Audio: pcm_s16le ([3][0][0][0] / 0x0003), 44100 Hz, 5.1, s16, 4233 kb/s (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
encoder : Lavc56.26.100 pcm_s16le
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
Stream #0:1 -> #0:1 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
frame= 812 fps= 93 q=-1.0 Lsize= 18938kB time=00:00:33.00 bitrate=4700.7kbits/s
video:1841kB audio:17056kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.214361%
[libx264 @ 0x914de0] frame I:23 Avg QP:16.97 size: 20207
[libx264 @ 0x914de0] frame P:294 Avg QP:20.61 size: 3904
[libx264 @ 0x914de0] frame B:495 Avg QP:23.24 size: 550
[libx264 @ 0x914de0] consecutive B-frames: 15.0% 7.9% 9.6% 67.5%
[libx264 @ 0x914de0] mb I I16..4: 34.6% 45.1% 20.3%
[libx264 @ 0x914de0] mb P I16..4: 3.5% 12.4% 0.8% P16..4: 19.1% 5.7% 2.4% 0.0% 0.0% skip:56.0%
[libx264 @ 0x914de0] mb B I16..4: 0.4% 0.4% 0.1% B16..8: 12.5% 1.0% 0.1% direct: 0.5% skip:85.1% L0:43.1% L1:50.9% BI: 5.9%
[libx264 @ 0x914de0] 8x8 transform intra:64.0% inter:75.7%
[libx264 @ 0x914de0] coded y,uvDC,uvAC intra: 33.0% 43.7% 13.4% inter: 4.1% 6.8% 1.0%
[libx264 @ 0x914de0] i16 v,h,dc,p: 53% 22% 9% 16%
[libx264 @ 0x914de0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27% 21% 27% 3% 5% 4% 5% 4% 4%
[libx264 @ 0x914de0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 20% 12% 5% 7% 9% 6% 8% 5%
[libx264 @ 0x914de0] i8c dc,h,v,p: 62% 20% 14% 5%
[libx264 @ 0x914de0] Weighted P-Frames: Y:32.0% UV:30.6%
[libx264 @ 0x914de0] ref P L0: 72.5% 16.1% 8.0% 3.3% 0.1%
[libx264 @ 0x914de0] ref B L0: 86.4% 11.6% 2.0%
[libx264 @ 0x914de0] ref B L1: 95.1% 4.9%
[libx264 @ 0x914de0] kb/s:464.26
ACTUALIZACIÓN 2:
ffmpeg -i sample.mkv -ac 6 -c copy sample.flv
ffmpeg version 2.6.2 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
configuration: --prefix=/opt/ffmpeg --libdir=/opt/ffmpeg/lib/ --enable-shared --enable-avresample --disable-stripping --enable-gpl --enable-version3 --enable-nonfree --enable-runtime-cpudetect --build-suffix=.ffmpeg --enable-postproc --enable-x11grab --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libdc1394 --enable-libfaac --enable-libfdk_aac --enable-libflite --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libvo-aacenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-openal --enable-opengl --enable-pthreads --enable-vaapi --enable-vdpau --enable-zlib --enable-debug=3
libavutil 54. 20.100 / 54. 20.100
libavcodec 56. 26.100 / 56. 26.100
libavformat 56. 25.101 / 56. 25.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 11.102 / 5. 11.102
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Guessed Channel Layout for Input Stream #0.1 : 5.1
Input #0, matroska,webm, from 'sample.mkv':
Metadata:
MINOR_VERSION : 512
COMPATIBLE_BRANDS: qt
MAJOR_BRAND : qt
ENCODER : Lavf56.25.101
Duration: 00:00:33.08, start: 0.080000, bitrate: 4691 kb/s
Stream #0:0(eng): Video: h264 (High), yuv420p, 854x480 [SAR 1:1 DAR 427:240], 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
ENCODER : Lavc56.26.100 libx264
Stream #0:1(eng): Audio: pcm_s16le, 44100 Hz, 6 channels, s16, 4233 kb/s (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
ENCODER : Lavc56.26.100 pcm_s16le
Output #0, flv, to 'sample.flv':
Metadata:
MINOR_VERSION : 512
COMPATIBLE_BRANDS: qt
MAJOR_BRAND : qt
encoder : Lavf56.25.101
Stream #0:0(eng): Video: h264 ([7][0][0][0] / 0x0007), yuv420p, 854x480 [SAR 1:1 DAR 427:240], q=2-31, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
ENCODER : Lavc56.26.100 libx264
Stream #0:1(eng): Audio: pcm_s16le ([3][0][0][0] / 0x0003), 44100 Hz, 5.1, 4233 kb/s (default)
Metadata:
LANGUAGE : eng
HANDLER_NAME : DataHandler
ENCODER : Lavc56.26.100 pcm_s16le
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 812 fps=0.0 q=-1.0 Lsize= 18968kB time=00:00:33.00 bitrate=4708.2kbits/s
video:1872kB audio:17056kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.214011%
Respuesta1
Hasta donde puedo decir, el formato FLV no admite oficialmente audio sin comprimir en formato PCM (consulte laEspecificaciones). Sin embargo, aún puedes multiplexar audio PCM en FLV con ffmpeg. Parece haber un error o incompatibilidad al ffplayno reproducir el audio correctamente, pero a mí me funciona en VLC:
ffmpeg -i sample.mkv -c copy sample.flv
Si deseas ser más compatible con otros reproductores, es posible que desees restringir el audio a dos canales. Para hacer eso:
ffmpeg -i sample.mkv -c:v copy -c:a pcm_s16le -ac 2 sample.flv
Esto reducirá la cantidad de canales de audio, pero no perderán calidad. La tasa de bits parecerá más baja, pero hay menos canales.
Tus otras opciones son audio AAC o audio MP3:
ffmpeg -i sample.mkv -c:v copy -c:a aac -strict experimental -b:a 128k sample.flv
ffmpeg -i sample.mkv -c:v copy -c:a libmp3lame sample.flv
Esto convertirá automáticamente el audio multicanal a estéreo.
Tenga en cuenta que si utiliza MP3 en FLV, estará restringido a las siguientes frecuencias de muestreo de audio: 44100, 22050, 11025. Esto se puede configurar con la -aropción oaresamplefiltrar.