[MPlayer-users] DVD temporary A/V desync on seek

[Ilja Sekler]

As already mentioned in
<http://lists.mplayerhq.hu/pipermail/mplayer-users/2010-January/078807.html>,
every seek when playing a video DVD results in warnings similar to

[mpeg2video @ 0x8922000]ignoring SEQ_START_CODE after 100
[mpeg2video @ 0x8922000]ignoring seq ext after 100
[mpeg2video @ 0x8922000]ignoring GOP_START_CODE after 100
[mpeg2video @ 0x8922000]ignoring pic after 100
[mpeg2video @ 0x8922000]Missing picture start code, guessing missing values

These warnings happen with all video DVDs for dvd:// and dvdnav:// I
tested so far.

The annoying issue for me is a big A/V desync on every seek including
navigating to a chapter, also when providing a -chapter parameter to
MPlayer. This desync (video is ahead of audio) persists for about 10
seconds, then the proper sync gets restored.

This may be negligible for movies, but, unfortunately, an A/V offset
beyond 100ms completely destroys the impression of unity between
movements of musicians and the resulting sound when watching recorded
classical concerts. The recordings are mostly from DVB-T, the DVDs are
unencrypted, of course.

Playing VOB files directly is fine, no desync on seek, no warnings, no
errors.

The full MPlayer output:


mplayer -v -dvd-device matthaeuspassion.iso dvd://1 -chapter 4
MPlayer SVN-r31016-4.4.1 (C) 2000-2010 MPlayer Team
CPU vendor name: AuthenticAMD  max cpuid level: 1
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ (Family: 15, Model:
75, Stepping: 2)
extended cpuid-level: 24
extended cache-info: 33587520
Detected cache-line size is 64 bytes
Testing OS support for SSE... yes.
Tests of OS support for SSE passed.
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNowExt: 1 SSE: 1 SSE2: 1 SSSE3: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowExt SSE SSE2 CMOV
get_path('codecs.conf') -> '/home/ilja/.mplayer/codecs.conf'
Reading /home/ilja/.mplayer/codecs.conf: 137 audio & 296 video codecs
Configuration: --prefix=/usr --disable-lirc --disable-gui
--target=i686-linux --confdir=/etc/mplayer
CommandLine: '-v' '-dvd-device' 'matthaeuspassion.iso' 'dvd://1'
'-chapter' '4'
init_freetype
Using MMX (with tiny bit MMX2) Optimized OnScreenDisplay
get_path('fonts') -> '/home/ilja/.mplayer/fonts'
Using nanosleep() timing
get_path('input.conf') -> '/home/ilja/.mplayer/input.conf'
Parsing input config file /home/ilja/.mplayer/input.conf
Input config file /home/ilja/.mplayer/input.conf parsed: 1 binds
get_path('1.conf') -> '/home/ilja/.mplayer/1.conf'

Playing dvd://1.
get_path('sub/') -> '/home/ilja/.mplayer/sub/'
URL: dvd://1
libdvdread: Using libdvdcss version 1.2.10 for DVD access
Reading disc structure, please wait...
There are 1 titles on this DVD.
There are 1 angles in this DVD title.

libdvdread: Attempting to retrieve all CSS keys
libdvdread: This can take a _long_ time, please be patient

libdvdread: Get key for /VIDEO_TS/VTS_01_1.VOB at 0x00000145
libdvdread: Elapsed time 0
libdvdread: Found 1 VTS's
libdvdread: Elapsed time 0
DVD successfully opened.
audio stream: 0 format: mpeg1 (stereo) language: de aid: 0.
number of audio channels on disk: 1.
number of subtitles on disk: 0
DVD start cell: 0  pack: 0x0-0x1E5F
DVD start=0 end=1501306
STREAM: [null] dvd://1
STREAM: Description: DVD stream
STREAM: Author:
STREAM: Comment:
DVD Seek! lba=0x0  cell=0  packs: 0x0-0x1E5F
Angle-seek synced by cell/vob IDN search!
system stream synced at 0xD (13)!
==> Found video stream: 0
MPEG-PS file format detected.
==> Found audio stream: 0

STREAM_DVD, seeked to chapter: 3, cell: 96451, pos: 197531648
DVD Seek! lba=0x178C3  cell=3  packs: 0x178C3-0x1DFD0
Angle-seek synced by cell/vob IDN search!
Searching for sequence header... OK!
VIDEO:  MPEG2  704x576  (aspect 3)  25.000 fps  1795.2 kbps (224.4 kbyte/s)
[V] filefmt:2  fourcc:0x10000002  size:704x576  fps:25.000  ftime:=0.0400
get_path('sub/') -> '/home/ilja/.mplayer/sub/'
X11 opening display: :0.0
vo: X11 color mask:  FFFFFF  (R:FF0000 G:FF00 B:FF)
vo: X11 running at 1280x1024 with depth 24 and 32 bpp (":0.0" => local
display)
[x11] Detected wm supports NetWM.
[x11] Detected wm supports FULLSCREEN state.
[x11] Detected wm supports ABOVE state.
[x11] Detected wm supports BELOW state.
[x11] Current fstype setting honours FULLSCREEN ABOVE BELOW X atoms
[VO_XV] Using Xv Adapter #0 (NV17 Video Texture)
[xv common] Drawing no colorkey.
[xv common] Maximum source image dimensions: 2046x2046
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 704 x 576 (preferred colorspace: Mpeg PES)
Trying filter chain: vo
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
SwScale params: -1 x -1 (-1=no scaling)
Trying filter chain: scale vo
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed :(
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
INFO: libavcodec init OK!
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
==========================================================================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
dec_audio: Allocating 4608 + 65536 = 70144 bytes for output buffer.
mp3lib: using 3DNow!Ex optimized decore!
MP3lib: init layer2&3 finished, tables done
MPEG 1.0, Layer II, 48000 Hz 192 kbit Stereo, BPF: 576
Channels: 2, copyright: No, original: Yes, CRC: Yes, emphasis: 0
AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
==========================================================================
Building audio filter chain for 48000Hz/2ch/s16le -> 0Hz/0ch/??...
[libaf] Adding filter dummy
[dummy] Was reinitialized: 48000Hz/2ch/s16le
[dummy] Was reinitialized: 48000Hz/2ch/s16le
Trying preferred audio driver 'pulse', options '[none]'
AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)
AO: Description: PulseAudio audio output
AO: Author: Lennart Poettering
Building audio filter chain for 48000Hz/2ch/s16le -> 48000Hz/2ch/s16le...
[dummy] Was reinitialized: 48000Hz/2ch/s16le
[dummy] Was reinitialized: 48000Hz/2ch/s16le
Starting playback...
Increasing filtered audio buffer size from 0 to 50048
[ffmpeg] aspect_ratio: 1.777778
VDec: vo config request - 704 x 576 (preferred colorspace: Planar YV12)
Trying filter chain: vo
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO Config (704x576->1024x576,flags=0,'MPlayer',0x32315659)
VO: [xv] 704x576 => 1024x576 Planar YV12
VO: Description: X11/Xv
VO: Author: Gerd Knorr <kraxel at goldbach.in-berlin.de> and others
Xvideo image format: 0x32595559 (YUY2) packed
Xvideo image format: 0x32315659 (YV12) planar
Xvideo image format: 0x59565955 (UYVY) packed
Xvideo image format: 0x30323449 (I420) planar
using Xvideo port 355 for hw scaling
*** [vo] Allocating (slices) mp_image_t, 704x576x12bpp YUV planar,
608256 bytes
*** [vo] Allocating (slices) mp_image_t, 704x576x12bpp YUV planar,
608256 bytes
Unicode font: 5025 glyphs.
Unicode font: 5025 glyphs.
*** [vo] Allocating (slices) mp_image_t, 704x576x12bpp YUV planar,
608256 bytes
DVD Seek! lba=0x178C3  cell=3  packs: 0x178C3-0x1DFD0  %  0.7% 4 0
Angle-seek synced by cell/vob IDN search!
DVD Seek! lba=0x18687  cell=3  packs: 0x178C3-0x1DFD0
Angle-seek synced by cell/vob IDN search!
[mpeg2video @ 0x8922000]ignoring SEQ_START_CODE after 100
[mpeg2video @ 0x8922000]ignoring seq ext after 100
[mpeg2video @ 0x8922000]ignoring GOP_START_CODE after 100
[mpeg2video @ 0x8922000]ignoring pic after 100
[mpeg2video @ 0x8922000]Missing picture start code, guessing missing values
Uninit audio filters...-0.454 ct: -0.308 486/486  9%  0%  0.8% 0 0
[libaf] Removing filter dummy
Uninit audio: mp3lib
Uninit video: ffmpeg
vo: uninit ...

Exiting... (Quit)

-- 
Regards

Ilja