[FFmpeg-devel] VQA v3 GSoC questions

[Vitor Sessak]

The Deep Explorer wrote:
> Hi ,
>     I am using 76B70801.VQA the v3 format.
> 
> /ffmpeg -i v3/nodlogo.vqa file.avi
> ############### DEEP just avcodec_register_all #########
> ############### DEEP just avdevice_register_all #########
> ############### DEEP just av_register_all #########
> [wsvqa @ 0x88b7ad0] note: unknown chunk seen (LINF)
> [wsvqa @ 0x88b7ad0]Skipping unknown chunk 0x534E324A
> [wsvqa @ 0x88b7ad0]VQFR_TAG
> [vqavideo @ 0x88c0d70]
> DEEP inside before avctx->codec->init
> [vqavideo @ 0x88c0d70]
> 
> ####### vqa_decode_init DEEP @@@@#########
> 
> [vqavideo @ 0x88c0d70] HI COLOR Implied 0
> [vqavideo @ 0x88c0d70] VQA VERSION : 3
> 
> 
> wsvqa @ 0x88b7ad0]Skipping unknown chunk 0x534E324A
> [wsvqa @ 0x88b7ad0]VQFR_TAG
> [wsvqa @ 0x88b7ad0]Skipping unknown chunk 0x534E324A

[...]

> [wsvqa @ 0x88b7ad0]Skipping unknown chunk 0x534E324A
> [wsvqa @ 0x88b7ad0]VQFR_TAG
> 
> 
> also when I let it go this is what I get :
> 
> DEEP >>>>>inside avcodec_decode_video <<<<
> [vqavideo @ 0x88c0d70] index ==> 0 size = 99262
> [vqavideo @ 0x88c0d70] CBFZ_TAG starts from 0  chunk Size 99232
> [vqavideo @ 0x88c0d70]  VQA video: Found unknown chunk type: VPRZ (5650525A)
> [vqavideo @ 0x88c0d70]  VQA video: problem: no VPTZ chunk found
> ###############output_packet calling before decoding  #########4.2kbits/s
> 
> 
> 
> For the v3 , it is mentioned in HC-VQA.TXT  that :
> " It appears the first CBFZ chunk comes inside the VQFR chunk  but the
> other ones seem to be located inside their own chunks,
>  called VQFL, which are followed by the usual VQFR chunks (containing
> VPTR/VPRZ chunks)."
> 
> I am guessing when it gets the VQFR I have to do something ...
> Please give me some pointers, kind of blocked...

The demuxer has to recognize the chunks to know if it is audio or video 
and send it to the right decoder. When the demuxer 
(libavformat/westwood.c) find a chunk it does not know, it just skip it, 
and it is what it is doing for VQFR chunks. Those chunks have to be send 
by the demuxer to video decoder (and the decoder should be modified to 
be able to decode them). So you should also do a few modifications to 
libavformat/westwood.c .

-Vitor