I've written a utility to author audio-only lpcm dvd's using mplex+dvdauthor; and though I'm feeding mplex audio and video of precisely equal duration, still get an audio gap at each chapter point. For instance using (24/96/2ch, NTSC)
chapter 1 :
A.lpcm=27027 frames (x 150 = 4054050 pts ticks)
A.m2v=1350 frames (x 3003 = 4054050 pts ticks)
chapter 2 :
B.lpcm=114114 frames (x 150 = 17117100 pts ticks)
B.m2v=5700 frames (x 3003 = 17117100 pts ticks)
etc...
which in theory are perfect matches, and yet I still get a distinct gap during playback on my actual dvd player as well as on VLC.
Neither mplex or dvdauthor issue any warnings, but report as you would expect...
INFO: [mplex] STREAM e0 completed @ frame 1349.
INFO: [mplex] STREAM bd completed @ frame 27026.
etc...
dvdauthor...
INFO: Video pts = 0.178 .. 45.223
INFO: Audio[16] pts = 0.178 .. 45.223
and so on (full output below)...
I should also say that the audio isn't padded but trimmed to length, and the video is via jpeg2yuv|mpeg2enc, and that dvdauthor is set to multiple chapters in one titleset, and that my mplex build is post my lpcm fixes to CVS of last fall.
Somewhere in the dvdauthor mailing list I ran across a similar situation with ac3 input, the user suspecting mplex's initial pts value at the chapter start point, though he gave no proof.
Since the ins and outs of pts represent a 'gap' in my own knowledge, I'm hoping the experts can fill me in,,,
Thanks,
Bahman
OUTPUT:
-------------------------------------------------------------------------
( mplex -f 8 -L 96000:2:24 -o "A.mpg" "A.m2v" "A.lpcm" )
INFO: [mplex] mplex version 1.8.0 (2.2.4 $Date: 2005/11/07 01:17:40 $)
INFO: [mplex] File A.m2v looks like an MPEG Video stream.
INFO: [mplex] File A.lpcm looks like an LPCM Audio stream.
INFO: [mplex] Video stream 0: profile 8 selected - ignoring non-standard options!
INFO: [mplex] Found 1 audio streams and 1 video streams
INFO: [mplex] Selecting dvdauthor DVD output profile
INFO: [mplex] Multiplexing video program stream!
INFO: [mplex] Scanning for header info: Video stream e0 (A.m2v)
INFO: [mplex] VIDEO STREAM: e0
INFO: [mplex] Frame width : 720
INFO: [mplex] Frame height : 480
INFO: [mplex] Aspect ratio : 4:3 display
INFO: [mplex] Picture rate : 29.970 frames/sec
INFO: [mplex] Bit rate : 5000000 bits/sec
INFO: [mplex] Vbv buffer size : 229376 bytes
INFO: [mplex] CSPF : 0
INFO: [mplex] Scanning for header info: LPCM Audio stream 00 (A.lpcm)
INFO: [mplex] LPCM AUDIO STREAM:
INFO: [mplex] Bit rate : 576000 bytes/sec (4608000) bit/sec)
INFO: [mplex] Channels : 2
INFO: [mplex] Bits per sample: 24
INFO: [mplex] Frequency : 96000 Hz
INFO: [mplex] SYSTEMS/PROGRAM stream:
INFO: [mplex] rough-guess multiplexed stream data rate : 9806200
INFO: [mplex] target data-rate specified : 10080000
INFO: [mplex] Setting specified specified data rate: 10080000
INFO: [mplex] Run-in Sectors = 89 Video delay = 13019 Audio delay = 16022
INFO: [mplex] New sequence commences...
INFO: [mplex] Video e0: buf= 0 frame=000000 sector=00000000
INFO: [mplex] Audio bd: buf= 0 frame=000000 sector=00000000
INFO: [mplex] Scanned to end AU 1349
INFO: [mplex] STREAM e0 completed @ frame 1349.
INFO: [mplex] STREAM bd completed @ frame 27026.
INFO: [mplex] Multiplex completion at SCR=4061330.
INFO: [mplex] Video e0: buf= 2212 frame=001349 sector=00001349
INFO: [mplex] Audio bd: buf= 56640 frame=027026 sector=00012948
INFO: [mplex] VIDEO_STATISTICS: e0
INFO: [mplex] Video Stream length: 2658063 bytes
INFO: [mplex] Sequence headers: 75
INFO: [mplex] Sequence ends : 1
INFO: [mplex] No. Pictures : 1350
INFO: [mplex] No. Groups : 75
INFO: [mplex] No. I Frames : 75 avg. size 7530 bytes
INFO: [mplex] No. P Frames : 376 avg. size 288 bytes
INFO: [mplex] No. B Frames : 899 avg. size 2208 bytes
INFO: [mplex] Average bit-rate : 472000 bits/sec
INFO: [mplex] Peak bit-rate : 472400 bits/sec
INFO: [mplex] BUFFERING min 174768 Buf max 184337
INFO: [mplex] AUDIO_STATISTICS: bd
INFO: [mplex] Audio stream length 25945920 bytes.
INFO: [mplex] Frames : 27026
INFO: [mplex] BUFFERING min 40 Buf max 1948
INFO: [mplex] MUX STATUS: no under-runs detected.
-------------------------------------------------------------------------
( mplex -f 8 -L 96000:2:24 -o "B.mpg" "B.m2v" "B.lpcm" )
INFO: [mplex] mplex version 1.8.0 (2.2.4 $Date: 2005/11/07 01:17:40 $)
INFO: [mplex] File B.m2v looks like an MPEG Video stream.
INFO: [mplex] File B.lpcm looks like an LPCM Audio stream.
INFO: [mplex] Video stream 0: profile 8 selected - ignoring non-standard options!
INFO: [mplex] Found 1 audio streams and 1 video streams
INFO: [mplex] Selecting dvdauthor DVD output profile
INFO: [mplex] Multiplexing video program stream!
INFO: [mplex] Scanning for header info: Video stream e0 (B.m2v)
INFO: [mplex] VIDEO STREAM: e0
INFO: [mplex] Frame width : 720
INFO: [mplex] Frame height : 480
INFO: [mplex] Aspect ratio : 4:3 display
INFO: [mplex] Picture rate : 29.970 frames/sec
INFO: [mplex] Bit rate : 5000000 bits/sec
INFO: [mplex] Vbv buffer size : 229376 bytes
INFO: [mplex] CSPF : 0
INFO: [mplex] Scanning for header info: LPCM Audio stream 00 (B.lpcm)
INFO: [mplex] LPCM AUDIO STREAM:
INFO: [mplex] Bit rate : 576000 bytes/sec (4608000) bit/sec)
INFO: [mplex] Channels : 2
INFO: [mplex] Bits per sample: 24
INFO: [mplex] Frequency : 96000 Hz
INFO: [mplex] SYSTEMS/PROGRAM stream:
INFO: [mplex] rough-guess multiplexed stream data rate : 9806200
INFO: [mplex] target data-rate specified : 10080000
INFO: [mplex] Setting specified specified data rate: 10080000
INFO: [mplex] Run-in Sectors = 89 Video delay = 13019 Audio delay = 16022
INFO: [mplex] New sequence commences...
INFO: [mplex] Video e0: buf= 0 frame=000000 sector=00000000
INFO: [mplex] Audio bd: buf= 0 frame=000000 sector=00000000
INFO: [mplex] Scanned to end AU 5699
INFO: [mplex] STREAM e0 completed @ frame 5699.
INFO: [mplex] STREAM bd completed @ frame 114113.
INFO: [mplex] Multiplex completion at SCR=17124205.
INFO: [mplex] Video e0: buf= 4420 frame=843889432 sector=00005700
INFO: [mplex] Audio bd: buf= 57600 frame=114113 sector=00054666
INFO: [mplex] VIDEO_STATISTICS: e0
INFO: [mplex] Video Stream length: 11231185 bytes
INFO: [mplex] Sequence headers: 317
INFO: [mplex] Sequence ends : 1
INFO: [mplex] No. Pictures : 5700
INFO: [mplex] No. Groups : 317
INFO: [mplex] No. I Frames : 317 avg. size 7529 bytes
INFO: [mplex] No. P Frames : 1584 avg. size 288 bytes
INFO: [mplex] No. B Frames : 3799 avg. size 2208 bytes
INFO: [mplex] Average bit-rate : 472400 bits/sec
INFO: [mplex] Peak bit-rate : 472400 bits/sec
INFO: [mplex] BUFFERING min 174768 Buf max 184337
INFO: [mplex] AUDIO_STATISTICS: bd
INFO: [mplex] Audio stream length 109549440 bytes.
INFO: [mplex] Frames : 114113
INFO: [mplex] BUFFERING min 40 Buf max 1948
INFO: [mplex] MUX STATUS: no under-runs detected.
etc....
----------------------------------------------------------------------------
DVDAuthor::dvdauthor, version 0.6.12-alpha-2907.
Build options: gnugetopt iconv freetype
Send bugs to <[EMAIL PROTECTED]>
INFO: Locale=C
INFO: Converting filenames to US-ASCII
INFO: dvdauthor creating VTS
STAT: Picking VTS 01
STAT: Processing A.mpg...
STAT: VOBU 64 at 23MB, 1 PGCS
INFO: Video pts = 0.178 .. 45.223
INFO: Audio[16] pts = 0.178 .. 45.223
STAT: Processing B.mpg...
STAT: VOBU 379 at 140MB, 1 PGCS
INFO: Video pts = 0.178 .. 190.368
INFO: Audio[16] pts = 0.178 .. 190.368
etc...
STAT: VOBU 10146 at 3794MB, 1 PGCS
INFO: Generating VTS with the following video attributes:
INFO: MPEG version: mpeg2
INFO: TV standard: ntsc
INFO: Aspect ratio: 4:3
INFO: Resolution: 720x480
INFO: Audio ch 0 format: pcm/2ch, 96khz 24bps
STAT: fixed 10146 VOBUS
INFO: dvdauthor creating table of contents
INFO: Scanning C:\(etc...)/VIDEO_TS/VTS_01_0.IFO
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