Ich habe eine Datei – sample.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
=========================================================
Ich möchte es über ffmpeg in einen FLV-Container umkodieren:
$ ffmpeg -i sample.mkv -b:a 4233k -c:v h264 -c:a pcm_s16le sample.flv
aber ich habe erhalten:
=========================================================
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
=========================================================
Warum wechselt die Bitrate von 4233000 auf 1411000?
Der Ton ist in dieser Hinsicht sehr schlecht :(
UPDATE vollständiges Protokoll
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
UPDATE 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%
Antwort1
Soweit ich weiß, unterstützt das FLV-Format offiziell kein unkomprimiertes Audio im PCM-Format (sieheSpezifikation). Sie können jedoch immer noch PCM-Audio mit ffmpeg in FLV multiplexen. Es scheint einen Fehler oder eine Inkompatibilität zu geben, die dazu führt, dass ffplaydas Audio nicht richtig abgespielt wird, aber bei mir funktioniert es in VLC:
ffmpeg -i sample.mkv -c copy sample.flv
Wenn Sie eine bessere Kompatibilität mit anderen Playern wünschen, können Sie den Ton auf zwei Kanäle beschränken. Gehen Sie dazu wie folgt vor:
ffmpeg -i sample.mkv -c:v copy -c:a pcm_s16le -ac 2 sample.flv
Dadurch wird die Anzahl der Audiokanäle reduziert, die Qualität geht jedoch nicht verloren. Die Bitrate sieht niedriger aus, aber es sind weniger Kanäle.
Sie haben außerdem die Wahl zwischen AAC-Audio und MP3-Audio:
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
Dadurch wird das Mehrkanal-Audio automatisch in Stereo umgewandelt.
Beachten Sie, dass Sie bei der Verwendung von MP3 in FLV auf die folgenden Audio-Abtastraten beschränkt sind: 44100, 22050, 11025. Dies kann mit der -arOption oder eingestellt werdenaresampleFilter.