[FFmpeg-soc] BFI Decoder

[Sisir Koppaka]

On Thu, Apr 17, 2008 at 3:17 AM, Michael Niedermayer <michaelni at gmx.at>
wrote:

> On Thu, Apr 17, 2008 at 03:16:29AM +0530, Sisir Koppaka wrote:
> > On Thu, Apr 17, 2008 at 3:15 AM, Mike Melanson <mike at multimedia.cx>
> wrote:
> >
> > > Sisir Koppaka wrote:
> > > > Only the first frame is shown and it's just a blue one... I think
> the
> > > frame
> > > > was not properly decoded though I can see the different parts of the
> > > switch
> > > > being executed from the av_logs...
> > >
> > > As Michael observed, you were calling FFmpeg in such a way that it was
> > > likely exiting before it even went into your decoder. Try adding a
> '-an'
> > > option so that audio is not decoded, or try my idea of just decoding
> > > individual picture frames.
> > >
> > Now, it's giving a segfault.
>
> gdb backtrace of ffmpeg_g of that will tell you where
>
on running ffmpeg_g inside gdb....

[DECODER] Back Chain.
Program received signal SIGSEGV, Segmentation fault.
0x08162dc9 in bfi_decode_frame (avctx=0x85e9400, data=0xbfe65508,
    data_size=0xbfe65638,
    buf=0x866bb7c
"BPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBP"...,
buf_size=476)
    at bfi.c:122
122                     *dst++ = *dst_offset++;
(gdb)
---------------------------------------------------------------
backtrace in gdb after running gives this:
[DECODER] Back Chain.
[DECODER] Back Chain.
Program received signal SIGSEGV, Segmentation fault.
0x08162dc9 in bfi_decode_frame (avctx=0x85e9400, data=0xbfe65508,
    data_size=0xbfe65638,
    buf=0x866bb7c
"BPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBP"...,
buf_size=476)
    at bfi.c:122
122                     *dst++ = *dst_offset++;
(gdb) backtrace
#0  0x08162dc9 in bfi_decode_frame (avctx=0x85e9400, data=0xbfe65508,
    data_size=0xbfe65638,
    buf=0x866bb7c
"BPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBP"...,
buf_size=476)
    at bfi.c:122
#1  0x080eb932 in avcodec_decode_video (avctx=0x85e9400, picture=0xbfe65508,

    got_picture_ptr=0xbfe65638,
    buf=0x866b480
"BPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBP"...,
buf_size=476)
    at utils.c:941
#2  0x08063655 in output_packet (ist=0x85f3a20, ist_index=0,
    ost_table=0x85f3af0, nb_ostreams=1, pkt=0xbfe65848) at ffmpeg.c:1112
#3  0x080659ec in main (argc=1112556112, argv=0x42504250) at ffmpeg.c:1992
(gdb)

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Sisir Koppaka