int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count) { int i, av_uninit(j); int current_ref_assigned = 0, err = 0; H264Picture *av_uninit(pic); if ((h->avctx->debug & FF_DEBUG_MMCO) && mmco_count == 0) av_log(h->avctx, AV_LOG_DEBUG, "no mmco here\n"); for (i = 0; i < mmco_count; i++) { int av_uninit(structure), av_uninit(frame_num); if (h->avctx->debug & FF_DEBUG_MMCO) av_log(h->avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode, h->mmco[i].short_pic_num, h->mmco[i].long_arg); if (mmco[i].opcode == MMCO_SHORT2UNUSED || mmco[i].opcode == MMCO_SHORT2LONG) { frame_num = pic_num_extract(h, mmco[i].short_pic_num, &structure); pic = find_short(h, frame_num, &j); if (!pic) { if (mmco[i].opcode != MMCO_SHORT2LONG || !h->long_ref[mmco[i].long_arg] || h->long_ref[mmco[i].long_arg]->frame_num != frame_num) { av_log(h->avctx, AV_LOG_ERROR, "mmco: unref short failure\n"); err = AVERROR_INVALIDDATA; } continue; } } switch (mmco[i].opcode) { case MMCO_SHORT2UNUSED: if (h->avctx->debug & FF_DEBUG_MMCO) av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n", h->mmco[i].short_pic_num, h->short_ref_count); remove_short(h, frame_num, structure ^ PICT_FRAME); break; case MMCO_SHORT2LONG: if (h->long_ref[mmco[i].long_arg] != pic) remove_long(h, mmco[i].long_arg, 0); remove_short_at_index(h, j); h->long_ref[ mmco[i].long_arg ] = pic; if (h->long_ref[mmco[i].long_arg]) { h->long_ref[mmco[i].long_arg]->long_ref = 1; h->long_ref_count++; } break; case MMCO_LONG2UNUSED: j = pic_num_extract(h, mmco[i].long_arg, &structure); pic = h->long_ref[j]; if (pic) { remove_long(h, j, structure ^ PICT_FRAME); } else if (h->avctx->debug & FF_DEBUG_MMCO) av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref long failure\n"); break; case MMCO_LONG: // Comment below left from previous code as it is an interresting note. /* First field in pair is in short term list or * at a different long term index. * This is not allowed; see 7.4.3.3, notes 2 and 3. * Report the problem and keep the pair where it is, * and mark this field valid. */ if (h->short_ref[0] == h->cur_pic_ptr) remove_short_at_index(h, 0); /* make sure the current picture is not already assigned as a long ref */ if (h->cur_pic_ptr->long_ref) { for (j = 0; j < FF_ARRAY_ELEMS(h->long_ref); j++) { if (h->long_ref[j] == h->cur_pic_ptr) remove_long(h, j, 0); } } if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) { remove_long(h, mmco[i].long_arg, 0); h->long_ref[mmco[i].long_arg] = h->cur_pic_ptr; h->long_ref[mmco[i].long_arg]->long_ref = 1; h->long_ref_count++; } h->cur_pic_ptr->reference |= h->picture_structure; current_ref_assigned = 1; break; case MMCO_SET_MAX_LONG: assert(mmco[i].long_arg <= 16); // just remove the long term which index is greater than new max for (j = mmco[i].long_arg; j < 16; j++) { remove_long(h, j, 0); } break; case MMCO_RESET: while (h->short_ref_count) { remove_short(h, h->short_ref[0]->frame_num, 0); } for (j = 0; j < 16; j++) { remove_long(h, j, 0); } h->frame_num = h->cur_pic_ptr->frame_num = 0; h->mmco_reset = 1; h->cur_pic_ptr->mmco_reset = 1; break; default: assert(0); } } if (!current_ref_assigned) { /* Second field of complementary field pair; the first field of * which is already referenced. If short referenced, it * should be first entry in short_ref. If not, it must exist * in long_ref; trying to put it on the short list here is an * error in the encoded bit stream (ref: 7.4.3.3, NOTE 2 and 3). */ if (h->short_ref_count && h->short_ref[0] == h->cur_pic_ptr) { /* Just mark the second field valid */ h->cur_pic_ptr->reference = PICT_FRAME; } else if (h->cur_pic_ptr->long_ref) { av_log(h->avctx, AV_LOG_ERROR, "illegal short term reference " "assignment for second field " "in complementary field pair " "(first field is long term)\n"); err = AVERROR_INVALIDDATA; } else { pic = remove_short(h, h->cur_pic_ptr->frame_num, 0); if (pic) { av_log(h->avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n"); err = AVERROR_INVALIDDATA; } if (h->short_ref_count) memmove(&h->short_ref[1], &h->short_ref[0], h->short_ref_count * sizeof(H264Picture*)); h->short_ref[0] = h->cur_pic_ptr; h->short_ref_count++; h->cur_pic_ptr->reference |= h->picture_structure; } } if (h->long_ref_count + h->short_ref_count - (h->short_ref[0] == h->cur_pic_ptr) > h->sps.ref_frame_count) { /* We have too many reference frames, probably due to corrupted * stream. Need to discard one frame. Prevents overrun of the * short_ref and long_ref buffers. */ av_log(h->avctx, AV_LOG_ERROR, "number of reference frames (%d+%d) exceeds max (%d; probably " "corrupt input), discarding one\n", h->long_ref_count, h->short_ref_count, h->sps.ref_frame_count); err = AVERROR_INVALIDDATA; if (h->long_ref_count && !h->short_ref_count) { for (i = 0; i < 16; ++i) if (h->long_ref[i]) break; assert(i < 16); remove_long(h, i, 0); } else { pic = h->short_ref[h->short_ref_count - 1]; remove_short(h, pic->frame_num, 0); } } print_short_term(h); print_long_term(h); return (h->avctx->err_recognition & AV_EF_EXPLODE) ? err : 0; }