[vlc] Re: [HOWARD JOHNSON <hwjohnso at adtran.com>] Dropping audio on high def clips

[Jean-Paul Saman]

Does this also occur in the case of using unicast?

And could you check on the VLC client when this happens if the audio is 
enabled? I have seen situations where VLC defaults to disabled audio on 
looping.

Greetings,
Jean-Paul Saman.

System administration wrote:

>----- Forwarded message from HOWARD JOHNSON <hwjohnso at adtran.com> -----
>
>From: HOWARD JOHNSON <hwjohnso at adtran.com>
>Date: Wed, 11 May 2005 15:35:26 -0500
>To: vlc at videolan.org
>Subject: Dropping audio on high def clips
>X-Spam-Status: No, score=1.2 required=5.0 tests=HTML_20_30,HTML_MESSAGE,
>	HTML_TAG_EXIST_TBODY,HTML_TITLE_EMPTY,MAILTO_LINK,SIGNATURE_DELIM,
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>
>I am having consistent, reproducible problems using VLC as server and 
>client with streaming/playing a looped MPEG-2 high definition video clip
>
>with A/52 audio encoding.  In a nutshelI, when looping this type of 
>video, every other iteration of the video looses sound for the entire 
>length of the clip.  So the 1st, 3rd, 5th, 7th etc... iterations play 
>fine for both audio and video but the 2nd, 4th, 6th etc... iterations 
>play only the video.  It seems as though the problem is with the 
>client.  If you stop the VLC client on an even number iteration and 
>restart the client then both audio and video play.
>
>The first set of messages captured show the A/52 audio stream detected 
>and the audio module a52 is selected.  The second set of messages shows 
>what happens with the 1st iteration ends and the 2nd begins.  For some 
>reason the audio stream is not detected.  And like I said, on the 3rd 
>iteration, the client re-dectects the A/52 audio and loads the a52 
>module and then both audio and video play normally.
>
>The server is invoked as follows:
>    "vlc Route_66.mpg  --sout-keep --loop --sout udp:224.1.1.1 --ttl 12"
>
>And the client is invoked as follows:
>    "vlc -vout x11 --nofullscreen udp://@224.1.1.1"
>
>This anomaly is happening on two different client machines running 
>vlc-0.8.1 but running different Linux distributions.
>
>Any ideas would be appreciated.
>
>main debug: looking for decoder module
>main debug: probing 19 candidates
>main debug: using decoder module "libmpeg2"
>a52: A/52 channels:2 samplerate:48000 bitrate:384000
>main debug: looking for audio output module
>main debug: probing 4 candidates
>main debug: thread 229386 (decoder) created at priority 0 
>(src/input/decoder.c:157)
>ts warning: first packet for pid=76 cc=0xf
>ts warning: discontinuity received 0x3 instead of 0xc
>alsa debug: opening ALSA device `default'
>libmpeg2 debug: 1920x1088, aspect 768000, 29.971 fps
>main warning: dts != current_pts (-2808074)
>main debug: thread 245766 (aout) created at priority 0 (alsa.c:603)
>main debug: using audio output module "alsa"
>main debug: output 'fl32' 48000 Hz Stereo frame=1 samples/8 bytes
>main debug: mixer 'fl32' 48000 Hz Stereo frame=1 samples/8 bytes
>main debug: no need for any filter
>main debug: looking for audio mixer module
>main debug: probing 3 candidates
>main debug: using audio mixer module "trivial_mixer"
>main debug: input 'a52 ' 48000 Hz Stereo frame=1536 samples/1536 bytes
>main debug: filter(s) 'a52 '->'fl32' 48000 Hz->48000 Hz Stereo->Stereo
>main debug: looking for audio filter module
>main debug: probing 22 candidates
>main debug: using audio filter module "a52tofloat32"
>main debug: found a filter for the whole conversion
>main debug: filter(s) 'fl32'->'fl32' 52800 Hz->48000 Hz Stereo->Stereo
>main debug: looking for audio filter module
>main debug: probing 22 candidates
>main debug: using audio filter module "bandlimited_resampler"
>main debug: found a filter for the whole conversion
>main warning: vout synchro warning: pts != current_date (-33355)
>main warning: late picture skipped (-10547)
>main debug: stream periodicity changed from B[1] to B[2]
>a52 debug: emulated sync word (no sync on following frame)
>main warning: buffer is 69723 in advance, triggering downsampling
>ts warning: discontinuity received 0xb instead of 0x1
>ts warning: discontinuity received 0xc instead of 0x8
>
>...snip
>
>ts debug: PMTCallBack called
>ts debug: new PMT program number=1 version=6 pid_pcr=78
>ts debug:   * es pid=78 type=129 fcc=a52
>ts debug:    * descriptor : unknown (0x5)
>ts debug:    * descriptor : unknown (0xa)
>main debug: unlocking module "a52"
>main debug: thread 213001 joined (src/input/decoder.c:189)
>main debug: killing decoder fourcc `a52 ', 49 PES in FIFO
>main debug: unlocking module "a52tofloat32"
>main debug: unlocking module "bandlimited_resampler"
>main debug: thread 245766 joined (alsa.c:655)
>main debug: unlocking module "alsa"
>main debug: unlocking module "trivial_mixer"
>main debug: unlocking module "libmpeg2"
>main debug: thread 229386 joined (src/input/decoder.c:189)
>main debug: killing decoder fourcc `mpgv', 60 PES in FIFO
>ts debug: PMTCallBack called
>ts debug: new PMT program number=1 version=7 pid_pcr=79
>ts debug:   * es pid=78 type=129 fcc=a52
>ts debug:    * descriptor : unknown (0x5)
>ts debug:    * descriptor : unknown (0xa)
>ts debug:   * es pid=79 type=2 fcc=mpgv
>main debug: looking for decoder module
>main debug: probing 19 candidates
>main debug: using decoder module "libmpeg2"
>main debug: thread 262150 (decoder) created at priority 0 
>(src/input/decoder.c:157)
>ts warning: first packet for pid=78 cc=0xf
>ts warning: discontinuity received 0x2 instead of 0xb
>libmpeg2 debug: 1920x1088, aspect 768000, 29.971 fps
>main warning: dts != current_pts (-2807333)
>main warning: late picture skipped (74948)
>main warning: vout synchro warning: pts != current_date (-33355)
>main debug: stream periodicity changed from B[1] to B[2]
>main debug: stream periodicity changed from P[5] to P[4]
>main debug: decoded 70/105 pictures
>
>  
>

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