[mythtv-users] Recordings Playback too fast on Frontend, fine on Backend

[jk90090]

Michael T. Dean wrote:
>
>> That would entail me ordering a card, ugh.
>> Ok, what's the best sub $75 sound card for Linux? 
>
> Don't buy a new one just to try.  Anyway, all the streams on the other 
> post were 48kHz, so it would appar there's something else to it--and 
> the fact that it's not chipmonk'ed supports that.
>
> Mike
More updates on this issue.  I tried playback on the same FE with 
mplayer ( /usr/bin/mplayer -fs -vo xv -ao alsa recording.mpg ) on the 
same content, yielded no issues with the video or audio playback (Stereo 
output). 

mplayer spit out the following for the first few seconds of the playback 
(still no playback issue onscreen though) :

TS file format detected.
VIDEO MPEG2(pid=1984) AUDIO A52(pid=1985) NO SUBS (yet)!  PROGRAM N. 1
VIDEO:  MPEG2  1280x720  (aspect 3)  59.940 fps  38810.4 kbps (4851.3 
kbyte/s)
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 1280 x 720 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDecoder init failed :(
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
==========================================================================
Opening audio decoder: [liba52] AC3 decoding with liba52
AUDIO: 48000 Hz, 2 ch, s16le, 448.0 kbit/29.17% (ratio: 56000->192000)
Selected audio codec: [a52] afm: liba52 (AC3-liba52)
==========================================================================
AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...
VDec: vo config request - 1280 x 720 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [xv] 1280x720 => 1280x720 Planar YV12  [fs]
A:77727.5 V:77727.8 A-V: -0.373 ct: -0.063  41/ 39 24%  4%  1.0% 0 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching 
framerate.
A:77727.5 V:77727.9 A-V: -0.375 ct: -0.067  44/ 41 24%  4%  1.0% 0 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
A:77728.4 V:77728.8 A-V: -0.393 ct: -0.118  96/ 71 18%  2%  0.8% 0 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching 
framerate.
A:77728.5 V:77728.9 A-V: -0.367 ct: -0.128 101/ 76 18%  1%  0.8% 0 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
A:77728.9 V:77729.3 A-V: -0.397 ct: -0.154 121/ 91 18%  1%  0.8% 0 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching 
framerate.
A:77729.1 V:77729.5 A-V: -0.335 ct: -0.174 131/101 17%  1%  0.8% 0 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
A:77734.1 V:77734.1 A-V: -0.001 ct: -0.502 407/347 16%  0%  0.8% 0 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching 
framerate.
A:77734.3 V:77734.3 A-V:  0.029 ct: -0.488 418/358 16%  0%  0.8% 0 0
demux_mpg: 30000/1001fps NTSC content detected, switching framerate.
A:77734.5 V:77734.5 A-V:  0.017 ct: -0.465 432/372 16%  0%  0.8% 0 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching 
framerate.

Next up, I used alsa spdif output:

/usr/bin/mplayer -fs -vo xv -ao alsa /recording.mpg

TS file format detected.
VIDEO MPEG2(pid=1984) AUDIO A52(pid=1985) NO SUBS (yet)!  PROGRAM N. 1
VIDEO:  MPEG2  1280x720  (aspect 3)  59.940 fps  38810.4 kbps (4851.3 
kbyte/s)
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 1280 x 720 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDecoder init failed :(
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
==========================================================================
Forced audio codec: hwac3
Opening audio decoder: [hwac3] AC3/DTS pass-through S/PDIF
hwac3: switched to AC3, 448000 bps, 48000 Hz
AUDIO: 48000 Hz, 2 ch, ac3, 448.0 kbit/29.17% (ratio: 56000->192000)
Selected audio codec: [hwac3] afm: hwac3 (AC3 through S/PDIF)
==========================================================================
AO: [alsa] 48000Hz 2ch ac3 (1 bytes per sample)
Starting playback...
VDec: vo config request - 1280 x 720 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [xv] 1280x720 => 1280x720 Planar YV12  [fs]
A:77727.5 V:77727.8 A-V: -0.374 ct: -0.063  41/ 39 23%  9%  0.6% 0 0
demux_mpg: 24000/1001fps progressive NTSC content detected, switching 
framerate.


Same perfect results, and over Dolby Digital as expected.

Everything now is pointing to a MythTV specific problem, and not Alsa or 
my audio setup.

Ideas? 

-JK