[FFmpeg-user] No audio on ffmpeg output

Laura Smith n5d9xq3ti233xiyif2vp at protonmail.ch
Thu Mar 4 19:07:43 EET 2021


Hi Phil

Just standard Mac OS X preview (click on a mp4 and hit space, it pops up a preview window and starts playing).  Doing so on the source file provides stereo audio output that is identical to what is seen in Adobe Premiere.  Doing so on the ffmpeg output provides pure silence.

Laura

Sent with ProtonMail Secure Email.

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Thursday, 4 March 2021 17:01, Phil Rhodes via ffmpeg-user <ffmpeg-user at ffmpeg.org> wrote:

> Hi Laura
> OK.
> Ordinarily I'd say unless the filenames literally contain your home address and phone number, don't obfuscate them, because that's exactly the sort of place the wet can get in.
> Still, in this case it does look like it's seeing the input audio and then writing about 4.5MB of audio data to the output.
> A couple of hopefully not daft questions:
>
> -   How are you ascertaining there's proper audio on the input? What software are you using to play the input file to check?- How are you ascertaining there's no audio on the output? What software are you using to play it back?
>     What I'm getting at here is that there is an audio track on the output, it just sounds like whatever you have isn't playing it back for some reason.
>     Try VLC? Where do you need it to work?
>     P
>     On Thursday, 4 March 2021, 16:38:50 GMT, Laura Smith via ffmpeg-user ffmpeg-user at ffmpeg.org wrote:
>
>
> Hi,
>
> The bit I posted was from a shell script so it was posted verbatim. The variables are being correctly substituted because $SOURCE is found and the output is at the expected $OUTDIR + $OUTPFX location.
>
> As for the output, see below.  I have changed filenames to obfuscated values because I don't fancy posting them to the wide internet !
>
> ffmpeg version N-101386-g77ce903f7a Copyright (c) 2000-2021 the FFmpeg developers
>   built with Apple clang version 12.0.0 (clang-1200.0.32.29)
>   configuration: --prefix=/Foobar/transcoding/build --x86asmexe=/Foobar/transcoding/build/bin/yasm --enable-libx264 --enable-gpl
>   libavutil      56. 66.100 / 56. 66.100
>   libavcodec     58.128.100 / 58.128.100
>   libavformat    58. 70.100 / 58. 70.100
>   libavdevice    58. 12.100 / 58. 12.100
>   libavfilter     7.107.100 /  7.107.100
>   libswscale      5.  8.100 /  5.  8.100
>   libswresample   3.  8.100 /  3.  8.100
>   libpostproc    55.  8.100 / 55.  8.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Path/To/My/Input.mp4':
>   Metadata:
>     major_brand     : mp42
>     minor_version   : 0
>     compatible_brands: mp42mp41
>     creation_time   : 2021-03-04T10:22:01.000000Z
>   Duration: 00:01:58.21, start: 0.000000, bitrate: 15825 kb/s
>   Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 15503 kb/s, 30 fps, 30 tbr, 30k tbn, 60k tbc (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : ?Mainconcept Video Media Handler
>       vendor_id       : [0][0][0][0]
>       encoder         : AVC Coding
>   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : #Mainconcept MP4 Sound Media Handler
>       vendor_id       : [0][0][0][0]
> Stream mapping:
>   Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
> Stream #0:1 -> #0:1 (copy)
> Press [q] to stop, [?] for help
> [libx264 @ 0x7fc39400f800] using SAR=1/1
> [libx264 @ 0x7fc39400f800] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
> [libx264 @ 0x7fc39400f800] profile High, level 4.2, 4:2:0, 8-bit
> [libx264 @ 0x7fc39400f800] 264 - core 161 r3048 b86ae3c - H.264/MPEG-4 AVC codec - Copyleft 2003-2021 - 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=24 lookahead_threads=4 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=72 keyint_min=37 scenecut=0 intra_refresh=0 rc_lookahead=40 rc=cbr mbtree=1 bitrate=6000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=6000 vbv_bufsize=6000 nal_hrd=none filler=0 ip_ratio=1.40 aq=1:1.00
> Output #0, mp4, to '/Path/To/My/1080/Output.mp4':
>   Metadata:
>     major_brand     : mp42
>     minor_version   : 0
>     compatible_brands: mp42mp41
>     encoder         : Lavf58.70.100
>   Stream #0:0(eng): Video: h264 (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 6000 kb/s, 30 fps, 15360 tbn (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : ?Mainconcept Video Media Handler
>       vendor_id       : [0][0][0][0]
>       encoder         : Lavc58.128.100 libx264
>     Side data:
>       cpb: bitrate max/min/avg: 6000000/0/6000000 buffer size: 6000000 vbv_delay: N/A
>   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : #Mainconcept MP4 Sound Media Handler
>       vendor_id       : [0][0][0][0]
> frame= 3545 fps= 70 q=-1.0 Lsize=   84120kB time=00:01:58.16 bitrate=5831.7kbits/s speed=2.33x   
> video:79412kB audio:4579kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.152952%
> [libx264 @ 0x7fc39400f800] frame I:50    Avg QP:13.83  size:144424
> [libx264 @ 0x7fc39400f800] frame P:1407  Avg QP:17.24  size: 41016
> [libx264 @ 0x7fc39400f800] frame B:2088  Avg QP:17.66  size:  7848
> [libx264 @ 0x7fc39400f800] consecutive B-frames:  2.5% 56.6%  0.8% 40.1%
> [libx264 @ 0x7fc39400f800] mb I  I16..4: 29.1% 53.4% 17.5%
> [libx264 @ 0x7fc39400f800] mb P  I16..4:  7.2% 16.7%  0.9%  P16..4: 33.1%  8.4%  5.6%  0.0%  0.0%    skip:28.1%
> [libx264 @ 0x7fc39400f800] mb B  I16..4:  1.2%  1.4%  0.0%  B16..8: 20.9%  1.6%  0.3%  direct: 6.0%  skip:68.5%  L0:35.1% L1:61.4% BI: 3.5%
> [libx264 @ 0x7fc39400f800] 8x8 transform intra:64.0% inter:67.9%
> [libx264 @ 0x7fc39400f800] coded y,uvDC,uvAC intra: 66.4% 79.2% 41.3% inter: 15.8% 24.6% 0.3%
> [libx264 @ 0x7fc39400f800] i16 v,h,dc,p: 21% 14% 55% 10%
> [libx264 @ 0x7fc39400f800] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 20% 15% 53%  2%  2%  2%  2%  2%  2%
> [libx264 @ 0x7fc39400f800] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 32% 25% 25%  3%  4%  3%  3%  3%  3%
> [libx264 @ 0x7fc39400f800] i8c dc,h,v,p: 52% 26% 19%  3%
> [libx264 @ 0x7fc39400f800] Weighted P-Frames: Y:0.4% UV:0.4%
> [libx264 @ 0x7fc39400f800] ref P L0: 71.0%  6.6% 14.2%  8.2%  0.0%
> [libx264 @ 0x7fc39400f800] ref B L0: 86.4% 10.4%  3.2%
> [libx264 @ 0x7fc39400f800] ref B L1: 97.9%  2.1%
> [libx264 @ 0x7fc39400f800] kb/s:5505.28
>
> ffmpeg version N-101386-g77ce903f7a Copyright (c) 2000-2021 the FFmpeg developers
>   built with Apple clang version 12.0.0 (clang-1200.0.32.29)
>   configuration: --prefix=/Foobar/transcoding/build --x86asmexe=/Foobar/transcoding/build/bin/yasm --enable-libx264 --enable-gpl
>   libavutil      56. 66.100 / 56. 66.100
>   libavcodec     58.128.100 / 58.128.100
>   libavformat    58. 70.100 / 58. 70.100
>   libavdevice    58. 12.100 / 58. 12.100
>   libavfilter     7.107.100 /  7.107.100
>   libswscale      5.  8.100 /  5.  8.100
>   libswresample   3.  8.100 /  3.  8.100
>   libpostproc    55.  8.100 / 55.  8.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Path/To/My/Input.mp4':
>   Metadata:
>     major_brand     : mp42
>     minor_version   : 0
>     compatible_brands: mp42mp41
>     creation_time   : 2021-03-04T10:22:01.000000Z
>   Duration: 00:01:58.21, start: 0.000000, bitrate: 15825 kb/s
>   Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 15503 kb/s, 30 fps, 30 tbr, 30k tbn, 60k tbc (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : ?Mainconcept Video Media Handler
>       vendor_id       : [0][0][0][0]
>       encoder         : AVC Coding
>   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : #Mainconcept MP4 Sound Media Handler
>       vendor_id       : [0][0][0][0]
> Stream mapping:
>   Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
> Stream #0:1 -> #0:1 (copy)
> Press [q] to stop, [?] for help
> [libx264 @ 0x7faa6a80f800] using SAR=1/1
> [libx264 @ 0x7faa6a80f800] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
> [libx264 @ 0x7faa6a80f800] profile Main, level 4.0, 4:2:0, 8-bit
> [libx264 @ 0x7faa6a80f800] 264 - core 161 r3048 b86ae3c - H.264/MPEG-4 AVC codec - Copyleft 2003-2021 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=22 lookahead_threads=3 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=72 keyint_min=37 scenecut=0 intra_refresh=0 rc_lookahead=40 rc=cbr mbtree=1 bitrate=3000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=3000 vbv_bufsize=3000 nal_hrd=none filler=0 ip_ratio=1.40 aq=1:1.00
> Output #0, mp4, to '/Path/To/My/720/Output.mp4':
>   Metadata:
>     major_brand     : mp42
>     minor_version   : 0
>     compatible_brands: mp42mp41
>     encoder         : Lavf58.70.100
>   Stream #0:0(eng): Video: h264 (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 3000 kb/s, 30 fps, 15360 tbn (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : ?Mainconcept Video Media Handler
>       vendor_id       : [0][0][0][0]
>       encoder         : Lavc58.128.100 libx264
>     Side data:
>       cpb: bitrate max/min/avg: 3000000/0/3000000 buffer size: 3000000 vbv_delay: N/A
>   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
>     Metadata:
>       creation_time   : 2021-03-04T10:22:01.000000Z
>       handler_name    : #Mainconcept MP4 Sound Media Handler
>       vendor_id       : [0][0][0][0]
> frame= 3545 fps=127 q=-1.0 Lsize=   42273kB time=00:01:58.16 bitrate=2930.7kbits/s speed=4.24x   
> video:37566kB audio:4579kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.304804%
> [libx264 @ 0x7faa6a80f800] frame I:50    Avg QP: 9.85  size:100765
> [libx264 @ 0x7faa6a80f800] frame P:890   Avg QP:15.30  size: 24723
> [libx264 @ 0x7faa6a80f800] frame B:2605  Avg QP:15.87  size:  4386
> [libx264 @ 0x7faa6a80f800] consecutive B-frames:  1.5%  0.3%  4.0% 94.2%
> [libx264 @ 0x7faa6a80f800] mb I  I16..4: 38.9%  0.0% 61.1%
> [libx264 @ 0x7faa6a80f800] mb P  I16..4:  4.8%  0.0%  3.6%  P16..4: 37.2% 17.6% 10.1%  0.0%  0.0%    skip:26.6%
> [libx264 @ 0x7faa6a80f800] mb B  I16..4:  0.4%  0.0%  0.1%  B16..8: 25.1%  2.2%  0.4%  direct: 7.6%  skip:64.1%  L0:37.0% L1:57.7% BI: 5.3%
> [libx264 @ 0x7faa6a80f800] coded y,uvDC,uvAC intra: 70.8% 84.9% 58.1% inter: 15.9% 27.8% 1.5%
> [libx264 @ 0x7faa6a80f800] i16 v,h,dc,p: 28%  9% 38% 26%
> [libx264 @ 0x7faa6a80f800] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 21% 26%  5%  5%  4%  4%  3%  3%
> [libx264 @ 0x7faa6a80f800] i8c dc,h,v,p: 57% 25% 14%  4%
> [libx264 @ 0x7faa6a80f800] Weighted P-Frames: Y:0.4% UV:0.4%
> [libx264 @ 0x7faa6a80f800] ref P L0: 59.8%  5.6% 22.8% 11.8%  0.0%
> [libx264 @ 0x7faa6a80f800] ref B L0: 84.9% 10.7%  4.4%
> [libx264 @ 0x7faa6a80f800] ref B L1: 97.7%  2.3%
> [libx264 @ 0x7faa6a80f800] kb/s:2604.24
>
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On Thursday, 4 March 2021 16:27, Phil Rhodes phil_rhodes at rocketmail.com wrote:
>
> > Hi there
> > Can I suggest you post for us the actual commandline that ends up getting executed, and the output from ffmpeg, at least until it gets down to the serious number crunching? The problem may be in the way the command is being assembled.
> > P
> > On Thursday, 4 March 2021, 16:18:15 GMT, Laura Smith via ffmpeg-user ffmpeg-user at ffmpeg.org wrote:
> > Hi,
> > Am I missing something simple here ?
> > The command I am using is based on the example given at https://google.github.io/shaka-packager/html/tutorials/encoding.html :
> > ffmpeg -i "${SOURCE}" -c:a copy \
> > -vf "scale=-2:1080" \
> > -c:v libx264 -profile:v high -level:v 4.2 \
> > -x264-params scenecut=0:open_gop=0:min-keyint=72:keyint=72 \
> > -minrate 6000k -maxrate 6000k -bufsize 6000k -b:v 6000k \
> > -y "${OUTDIR}/1080/${OUTPFX}_1080.mp4"
> > ffmpeg -i "${SOURCE}" -c:a copy \
> > -vf "scale=-2:720" \
> > -c:v libx264 -profile:v main -level:v 4.0 \
> > -x264-params scenecut=0:open_gop=0:min-keyint=72:keyint=72 \
> > -minrate 3000k -maxrate 3000k -bufsize 3000k -b:v 3000k \
> > -y "${OUTDIR}/720/${OUTPFX}_720.mp4"
> > The source file (an mp4 output from Adobe premiere) audio is perfect, no problems. So there is something happening at the ffmpeg stage ?
> > Where am I going wrong ?
> > Thanks !
> > Laura
> >
> > ffmpeg-user mailing list
> > ffmpeg-user at ffmpeg.org
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