I have been investigating
the issue, for some time.
Trying to find out of
problem was caused by read errors, and trying to locate the problem.
What I have done is fix
cache and device io in Mplayer as it was broken, I was hoping by
doing this the problem was going to go away.
But what it did was, it
enabled mplayer to pre buffer 999999 bytes, but as soon as the buffer
runs out mplayer is back to crawl speed.
I have tried to compile
the latest version of mplayer and ffmpeg, and the problem remains. I
have tried to read from the filesystem instead of depending on the IO
system, by fixing that part of the code as it was broken as well, but
there is no luck there, reading a DVD is not like reading a file.
I measured the read speed, at device IO in libdvdcss/device.c and found the 38KB/s read speed, so in other words, the read speed is low, it should be around 1.49MB/s, so we are not even close, to be playable.
I made some tests to see what best copy speed was, I copied a 972Mb file in 372 sec, or 2.6Mb/s, so this is not a hardware problem, the problem most be with DVD://1 DVDNAV://1 -dvd-device option.
I can play the a VOB file from a DVD disc, with some cache, but only this way I get good speed, with out cache its just as slow as the DVD://1 DVDNAV://1 options.
I have taken the time to
look at the status line in mplayer, it says some thing like:
A: 13.1 B: 3.2 A-V: 9.981
ct: 0.051 77/155 39% 24% 10192.1% 153 0
So what this status line
says is that A: is for audio, it represent the time played for audio,
and V: for video, A-V: is the out of sync number it should be 0,
77/155 is decoded vs the not yet decoded frames in buffer, 29% is
codec, 24% is the video, and 10192.1% is the audio,
the the biggest problem
looks to be related to audio, but its not really, the high number
comes because the audio buffer is empty and the audio cache has to be
filled, so I tried to trace the it up stream, from main loop in
mplayer.c, but it was not easy.
So then I remembered about
debug features in AmigaOS4.1, so I decided to collect some
information using stacktrace feature.
There was a problem it
required the task I wanted to be halted, while using back trace, but
that was lucky not a issue for me, as device io code was moved into a
different task of its own, to prevent problems with treading in
mplayer, and task that issues the read waits for signal for data to
be ready, so I was happy about that, if not might not have tried
this.
Anyway here is stack
traces I made, using Exec debug interface.
Stack:
kernel : NULL
kernel : NULL
mplayer :
dvdcss_seek
mplayer : css_seek
mplayer :
UDFReadBlocksRaw
mplayer :
DVDReadBytes
mplayer :
ifoRead_PGC
mplayer :
ifoRead_PGCIT_internal
mplayer :
ifoRead_PGCI_UT
mplayer : ifoOpen
mplayer : open_s
mplayer :
open_stream_full
mplayer :
open_stream
mplayer : main
newlib.library.kmod
: NULL
newlib.library.kmod
: NULL
newlib.library.kmod
: NULL
mplayer : _start
dos.library.kmod :
NULL
kernel : NULL
kernel : NULL
Stack:
kernel : NULL
kernel : NULL
mplayer :
dvdcss_seek
mplayer : css_seek
mplayer :
UDFReadBlocksRaw
mplayer :
fill_buffer
mplayer :
stream_read_internal
mplayer :
stream_fill_buffer
mplayer :
cache_stream_fill_buffer
mplayer :
demux_mpg_fill_buffer
mplayer :
ds_fill_buffer
mplayer :
ds_get_packet_pts
mplayer :
decode_audio
mplayer :
mp_decode_audio
mplayer : main
newlib.library.kmod
: NULL
newlib.library.kmod
: NULL
newlib.library.kmod
: NULL
mplayer : _start
dos.library.kmod :
NULL
kernel : NULL
kernel : NULL
Stack:
kernel : NULL
kernel : NULL
mplayer :
dvdcss_read
mplayer : css_read
mplayer :
UDFReadBlocksRaw
mplayer :
fill_buffer
mplayer :
stream_read_internal
mplayer :
stream_fill_buffer
mplayer :
cache_stream_fill_buffer
mplayer :
demux_mpg_fill_buffer
mplayer :
ds_fill_buffer
mplayer :
ds_get_packet_pts
mplayer :
decode_audio
mplayer :
mp_decode_audio
mplayer : main
newlib.library.kmod
: NULL
newlib.library.kmod
: NULL
newlib.library.kmod
: NULL
mplayer : _start
dos.library.kmod :
NULL
kernel : NULL
kernel : NULL
So I hope this
information is useful to find out where the problem comes from, if
not it gives a good overview of where problem might be located I
hope.
The problem with
mplayer is to get a overview, anyway if
anyone knows about free vitalization tool, to get some overview of
this source code it might be rally useful.
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