[vlc-devel] Some advice on Kasenna trickplay support...

[Glen Gray]

Hey Guys,

I'm kind of wandering around in the dark a little here. So some  
advice on what I need to look at would be most appreciative.

Testing this patch using the RC interface. I've got fastforward  
calling the demux2_Control function of livedotcom.cpp and triggering  
a section called  DEMUX_SET_RATE:. This basically
pauses the Kasenna server and then triggers a playMediaSession with  
the play rate set to 12. This is correctly passed up to the Kasenna  
and I can see from it's logs that it starts playing at x12. The  
INPUT_RATE_MIN and INPUT_RATE_MAX are used to flags in the code  
rather than using the values, you'll see debug stating the  
INPUT_RATE_MIN below. The code just compares the rate value against  
the defines to see if it's ff or rw that is required.

So, now I've the Kasenna doing the fastforward, I need to be able to  
play what it's sending down. And this is where I'm having trouble.  
I'm a total noob when it comes to mpeg etc. so please be forgiving if  
the answer is obvious :)

I've based my patch off of Dermot's previous patch and removed  
anything other than the code required to set the rate on the server.  
So now I guess I need to fiddle with the streams rate and timers ?

[00000460] livedotcom demuxer warning: DEMUX_SET_RATE returning  
VLC_SUCCESS
[00000459] main input warning: called demux set rate with 125
libdvbpsi error (PSI decoder): TS discontinuity (received 0, expected 1)
[00000462] ts demuxer debug: PATCallBack called
libdvbpsi error (PSI decoder): TS discontinuity (received 15,  
expected 1)
[00000462] ts demuxer debug: PMTCallBack called
[00000462] ts demuxer debug: new PMT program number=1 version=31  
pid_pcr=4131
[00000313] main module debug: unlocking module "mpeg_audio"
[00000463] main decoder debug: thread 86469552 joined (src/input/ 
decoder.c:191)
[00000463] main decoder debug: killing decoder fourcc `mpga', 2 PES  
in FIFO
[00000275] main module debug: unlocking module "mpgatofixed32"
[00000262] main module debug: unlocking module "bandlimited_resampler"
[00000468] main audio output debug: thread 3069234096 joined (alsa.c: 
667)
[00000291] main module debug: unlocking module "alsa"
[00000289] main module debug: unlocking module "trivial_mixer"
[00000310] main module debug: unlocking module "libmpeg2"
[00000464] main decoder debug: thread 152705968 joined (src/input/ 
decoder.c:191)[00000464] main decoder debug: killing decoder fourcc  
`mpgv', 58 PES in FIFO
[00000459] main input debug: Program doesn't contain anymore ES
[00000462] ts demuxer debug: PMTCallBack called
[00000462] ts demuxer debug: new PMT program number=1 version=0  
pid_pcr=4131
[00000462] ts demuxer debug:  * descriptor : unknown (0x17)
[00000462] ts demuxer debug:   * es pid=4131 type=2 fcc=mpgv
[00000471] main decoder debug: looking for decoder module: 20 candidates
[00000310] main module debug: using decoder module "libmpeg2"
[00000471] main decoder debug: thread 152705968 (decoder) created at  
priority 0 (src/input/decoder.c:159)
[00000462] ts demuxer debug:   * es pid=4130 type=3 fcc=mpga
[00000472] main decoder debug: looking for decoder module: 20 candidates
[00000313] main module debug: using decoder module "mpeg_audio"
[00000472] main decoder debug: thread 3069234096 (decoder) created at  
priority 0 (src/input/decoder.c:159)
[00000462] ts demuxer warning: first packet for pid=4131 cc=0xf
[00000459] main input warning: clock gap, unexpected stream  
discontinuity
libdvbpsi error (PSI decoder): TS discontinuity (received 0, expected 1)
[00000462] ts demuxer debug: PATCallBack called
libdvbpsi error (PSI decoder): TS discontinuity (received 0, expected 1)
[00000462] ts demuxer debug: PMTCallBack called
[00000471] libmpeg2 decoder debug: 704x480, aspect 576000, 29.971 fps
[00000461] main private debug: thread 75979696: secret message  
triggered at src/misc/block.c:227 (Connection timed out)
[00000471] main decoder debug: thread 152705968: secret message  
triggered at src/misc/block.c:227 (Connection timed out)
[00000472] main decoder debug: thread 3069234096: secret message  
triggered at src/misc/block.c:227 (Connection timed out)


Here is the patch I'm using.
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-- 
Glen Gray <glen at lincor.com>              Digital Depot, Thomas Street
Senior Software Engineer                            Dublin 8, Ireland
Lincor Solutions Ltd.                          Ph: +353 (0) 1 4893682