On Mon, Apr 6, 2015 at 2:02 PM, Mathieu Malaterre <[email protected]> wrote: > On Sat, Apr 4, 2015 at 6:48 PM, Luca Barbato <[email protected]> wrote: >> On 04/04/15 15:23, Mathieu Malaterre wrote: >>> Hi, >>> >>> I am trying to understand why avconv is breaking sound on a working >>> AVI input. I can play a video on my FreeBox V5 just fine. However >>> after copy: >>> >>> $ avconv -i input.avi -codec copy output.avi >>> >>> The generated `output.avi` appears as non working on my FreeBox V5 >>> player. If I compare (avprobe -show_streams) here is what I see: >>> >>> $ avprobe -show_streams input.avi > /tmp/1 >>> $ avprobe -show_streams output.avi > /tmp/2 >>> $ diff -u /tmp/1 /tmp/2 >>> --- /tmp/1 2015-04-04 15:13:53.222288651 +0200 >>> +++ /tmp/2 2015-04-04 15:19:19.898275904 +0200 >>> @@ -26,15 +26,15 @@ >>> codec_long_name=ATSC A/52A (AC-3) >>> codec_type=audio >>> codec_time_base=1/48000 >>> -codec_tag_string=[0] [0][0] >>> -codec_tag=0x2000 >>> +codec_tag_string=[254][255][0][0] >>> +codec_tag=0xfffe >>> sample_rate=48000.000000 >>> channels=6 >>> bits_per_sample=0 >>> r_frame_rate=0/0 >>> -avg_frame_rate=125/4 >>> -time_base=1/56000 >>> +avg_frame_rate=0/0 >>> +time_base=4/125 >>> start_time=0.000000 >>> duration=N/A >>> -nb_frames=127391040 >>> +nb_frames=33174 >>> [/STREAM] >>> >>> Does the `codec_tag_string` value have any influence here ? >> >> I think so, if you add -tag:a 0x2000 does it work? > > Now I have: > > $ diff -u /tmp/1 /tmp/2 > --- /tmp/1 2015-04-06 13:50:25.906181310 +0200 > +++ /tmp/2 2015-04-06 13:55:36.833418214 +0200 > @@ -35,7 +35,7 @@ > bits_per_sample=0 > avg_frame_rate=0/0 > bit_rate=448000.000000 > -time_base=1/56000 > +time_base=4/125 > start_time=0.000000 > duration=N/A > nb_frames=127391040 > > However I can still not hear a thing on the generated file... > > In summary, none of the following generates a file with working sound > (while input.avi is ok): > > $ avconv -i input.avi -codec copy test_copy.avi > $ avconv -i input.avi -codec copy -tag:a 0x2000 test_copy.avi
I can generate AVI with working sound using only 2 channels: $ avconv -i input.avi -vcodec copy -acodec ac3 -ac 2 test_copy.avi In order to keep all Channels (dolby 5.1 ac3 input), I need to use mkv container with h264 video stream: $ avconv -i input.avi -vcodec h264 -preset slow -tune animation -crf 18 -acodec copy test_copy.mkv Tests were conducted on FreeBox V5 (Firmware 1.5.20) -- Mathieu _______________________________________________ libav-tools mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-tools
