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VLC 2.1.3 Crash on mpeg12dec.c

Posted: 29 Nov 2013 01:02
by Gobelz
Hi all,

I'm having troubles with VLC for iOS. I stream video on my iPad and sometimes the app crashes (when the stream is poor) on mpeg12dec.c

I don't know why, and I'm wondering if there is anyone who can help me.

This is the method with the crash (Thread 19: EXC_BAD_ACCES)

if (level != 0) {
i += run;
j = scantable; THE APP CRASHES ON THIS LINE

Code: Select all

static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, int16_t *block, int n) { int level, i, j, run; RLTable *rl = &ff_rl_mpeg1; uint8_t * const scantable = s->intra_scantable.permutated; const int qscale = s->qscale; OPEN_READER(re, &s->gb); i = -1; // special case for first coefficient, no need to add second VLC table UPDATE_CACHE(re, &s->gb); if (((int32_t)GET_CACHE(re, &s->gb)) < 0) { level = (3 * qscale) >> 1; if (GET_CACHE(re, &s->gb) & 0x40000000) level = -level; block[0] = level; i++; SKIP_BITS(re, &s->gb, 2); if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF) goto end; } /* now quantify & encode AC coefficients */ for (;;) { GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0); if (level != 0) { i += run; j = scantable[i]; [color=#FF0000] THE APP CRASHES ON THIS LINE[/color] level = ((level * 2 + 1) * qscale) >> 1; level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1); } else { /* escape */ run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6); UPDATE_CACHE(re, &s->gb); level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12); i += run; j = scantable[i]; if (level < 0) { level = ((-level * 2 + 1) * qscale) >> 1; level = -level; } else { level = ((level * 2 + 1) * qscale) >> 1; } } block[j] = level; if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF) break; UPDATE_CACHE(re, &s->gb); } end: LAST_SKIP_BITS(re, &s->gb, 2); CLOSE_READER(re, &s->gb); s->block_last_index[n] = i; return 0; }
Thanks,

Re: VLC 2.1.3 Crash on mpeg12dec.c

Posted: 29 Nov 2013 21:09
by Gobelz
Any idea's? I'm wondering who is familiar with this issue..

Re: VLC 2.1.3 Crash on mpeg12dec.c

Posted: 09 Dec 2013 17:45
by Jean-Baptiste Kempf
Ask on #ffmpeg-dev on Freenode