On 07/04/15 10:26, Mathieu Malaterre wrote:
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)
Ok, so the problem is in the avi muxer, can you please provide a sample
file working on the freebox? I'm not sure when I'll have the time to fix
the issue but it is worth some investigation.
lu
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