/* * H.26L/H.264/AVC/JVT/14496-10/... reference picture handling * Copyright (c) 2003 Michael Niedermayer * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * H.264 / AVC / MPEG-4 part10 reference picture handling. * @author Michael Niedermayer */ #include #include "internal.h" #include "avcodec.h" #include "h264.h" #include "golomb.h" #include "mpegutils.h" #include static void pic_as_field(H264Ref *pic, const int parity) { int i; for (i = 0; i < FF_ARRAY_ELEMS(pic->data); ++i) { if (parity == PICT_BOTTOM_FIELD) pic->data[i] += pic->linesize[i]; pic->reference = parity; pic->linesize[i] *= 2; } pic->poc = pic->parent->field_poc[parity == PICT_BOTTOM_FIELD]; } static void ref_from_h264pic(H264Ref *dst, H264Picture *src) { memcpy(dst->data, src->f->data, sizeof(dst->data)); memcpy(dst->linesize, src->f->linesize, sizeof(dst->linesize)); dst->reference = src->reference; dst->poc = src->poc; dst->pic_id = src->pic_id; dst->parent = src; } static int split_field_copy(H264Ref *dest, H264Picture *src, int parity, int id_add) { int match = !!(src->reference & parity); if (match) { ref_from_h264pic(dest, src); if (parity != PICT_FRAME) { pic_as_field(dest, parity); dest->pic_id *= 2; dest->pic_id += id_add; } } return match; } static int build_def_list(H264Ref *def, int def_len, H264Picture * const *in, int len, int is_long, int sel) { int i[2] = { 0 }; int index = 0; while ((i[0] < len || i[1] < len) && index < def_len) { while (i[0] < len && !(in[i[0]] && (in[i[0]]->reference & sel))) i[0]++; while (i[1] < len && !(in[i[1]] && (in[i[1]]->reference & (sel ^ 3)))) i[1]++; if (i[0] < len && index < def_len) { in[i[0]]->pic_id = is_long ? i[0] : in[i[0]]->frame_num; split_field_copy(&def[index++], in[i[0]++], sel, 1); } if (i[1] < len && index < def_len) { in[i[1]]->pic_id = is_long ? i[1] : in[i[1]]->frame_num; split_field_copy(&def[index++], in[i[1]++], sel ^ 3, 0); } } return index; } static int add_sorted(H264Picture **sorted, H264Picture * const *src, int len, int limit, int dir) { int i, best_poc; int out_i = 0; for (;;) { best_poc = dir ? INT_MIN : INT_MAX; for (i = 0; i < len; i++) { const int poc = src[i]->poc; if (((poc > limit) ^ dir) && ((poc < best_poc) ^ dir)) { best_poc = poc; sorted[out_i] = src[i]; } } if (best_poc == (dir ? INT_MIN : INT_MAX)) break; limit = sorted[out_i++]->poc - dir; } return out_i; } static void h264_initialise_ref_list(const H264Context *h, H264SliceContext *sl) { int i, len; if (sl->slice_type_nos == AV_PICTURE_TYPE_B) { H264Picture *sorted[32]; int cur_poc, list; int lens[2]; if (FIELD_PICTURE(h)) cur_poc = h->cur_pic_ptr->field_poc[h->picture_structure == PICT_BOTTOM_FIELD]; else cur_poc = h->cur_pic_ptr->poc; for (list = 0; list < 2; list++) { len = add_sorted(sorted, h->short_ref, h->short_ref_count, cur_poc, 1 ^ list); len += add_sorted(sorted + len, h->short_ref, h->short_ref_count, cur_poc, 0 ^ list); assert(len <= 32); len = build_def_list(sl->ref_list[list], FF_ARRAY_ELEMS(sl->ref_list[0]), sorted, len, 0, h->picture_structure); len += build_def_list(sl->ref_list[list] + len, FF_ARRAY_ELEMS(sl->ref_list[0]) - len, h->long_ref, 16, 1, h->picture_structure); if (len < sl->ref_count[list]) memset(&sl->ref_list[list][len], 0, sizeof(H264Ref) * (sl->ref_count[list] - len)); lens[list] = len; } if (lens[0] == lens[1] && lens[1] > 1) { for (i = 0; i < lens[0] && sl->ref_list[0][i].parent->f->buf[0]->buffer == sl->ref_list[1][i].parent->f->buf[0]->buffer; i++); if (i == lens[0]) { FFSWAP(H264Ref, sl->ref_list[1][0], sl->ref_list[1][1]); } } } else { len = build_def_list(sl->ref_list[0], FF_ARRAY_ELEMS(sl->ref_list[0]), h->short_ref, h->short_ref_count, 0, h->picture_structure); len += build_def_list(sl->ref_list[0] + len, FF_ARRAY_ELEMS(sl->ref_list[0]) - len, h-> long_ref, 16, 1, h->picture_structure); if (len < sl->ref_count[0]) memset(&sl->ref_list[0][len], 0, sizeof(H264Ref) * (sl->ref_count[0] - len)); } } /** * print short term list */ static void print_short_term(const H264Context *h) { uint32_t i; if (h->avctx->debug & FF_DEBUG_MMCO) { av_log(h->avctx, AV_LOG_DEBUG, "short term list:\n"); for (i = 0; i < h->short_ref_count; i++) { H264Picture *pic = h->short_ref[i]; av_log(h->avctx, AV_LOG_DEBUG, "%"PRIu32" fn:%d poc:%d %p\n", i, pic->frame_num, pic->poc, pic->f->data[0]); } } } /** * print long term list */ static void print_long_term(const H264Context *h) { uint32_t i; if (h->avctx->debug & FF_DEBUG_MMCO) { av_log(h->avctx, AV_LOG_DEBUG, "long term list:\n"); for (i = 0; i < 16; i++) { H264Picture *pic = h->long_ref[i]; if (pic) { av_log(h->avctx, AV_LOG_DEBUG, "%"PRIu32" fn:%d poc:%d %p\n", i, pic->frame_num, pic->poc, pic->f->data[0]); } } } } /** * Extract structure information about the picture described by pic_num in * the current decoding context (frame or field). Note that pic_num is * picture number without wrapping (so, 0<=pic_numpicture_structure; if (FIELD_PICTURE(h)) { if (!(pic_num & 1)) /* opposite field */ *structure ^= PICT_FRAME; pic_num >>= 1; } return pic_num; } static void h264_fill_mbaff_ref_list(H264SliceContext *sl) { int list, i, j; for (list = 0; list < sl->list_count; list++) { for (i = 0; i < sl->ref_count[list]; i++) { H264Ref *frame = &sl->ref_list[list][i]; H264Ref *field = &sl->ref_list[list][16 + 2 * i]; field[0] = *frame; for (j = 0; j < 3; j++) field[0].linesize[j] <<= 1; field[0].reference = PICT_TOP_FIELD; field[0].poc = field[0].parent->field_poc[0]; field[1] = field[0]; for (j = 0; j < 3; j++) field[1].data[j] += frame->parent->f->linesize[j]; field[1].reference = PICT_BOTTOM_FIELD; field[1].poc = field[1].parent->field_poc[1]; } } } int ff_h264_build_ref_list(const H264Context *h, H264SliceContext *sl) { int list, index, pic_structure; print_short_term(h); print_long_term(h); h264_initialise_ref_list(h, sl); for (list = 0; list < sl->list_count; list++) { int pred = h->curr_pic_num; for (index = 0; index < sl->nb_ref_modifications[list]; index++) { unsigned int modification_of_pic_nums_idc = sl->ref_modifications[list][index].op; unsigned int val = sl->ref_modifications[list][index].val; unsigned int pic_id; int i; H264Picture *ref = NULL; switch (modification_of_pic_nums_idc) { case 0: case 1: { const unsigned int abs_diff_pic_num = val + 1; int frame_num; if (abs_diff_pic_num > h->max_pic_num) { av_log(h->avctx, AV_LOG_ERROR, "abs_diff_pic_num overflow\n"); return AVERROR_INVALIDDATA; } if (modification_of_pic_nums_idc == 0) pred -= abs_diff_pic_num; else pred += abs_diff_pic_num; pred &= h->max_pic_num - 1; frame_num = pic_num_extract(h, pred, &pic_structure); for (i = h->short_ref_count - 1; i >= 0; i--) { ref = h->short_ref[i]; assert(ref->reference); assert(!ref->long_ref); if (ref->frame_num == frame_num && (ref->reference & pic_structure)) break; } if (i >= 0) ref->pic_id = pred; break; } case 2: { int long_idx; pic_id = val; // long_term_pic_idx long_idx = pic_num_extract(h, pic_id, &pic_structure); if (long_idx > 31) { av_log(h->avctx, AV_LOG_ERROR, "long_term_pic_idx overflow\n"); return AVERROR_INVALIDDATA; } ref = h->long_ref[long_idx]; assert(!(ref && !ref->reference)); if (ref && (ref->reference & pic_structure)) { ref->pic_id = pic_id; assert(ref->long_ref); i = 0; } else { i = -1; } break; } } if (i < 0) { av_log(h->avctx, AV_LOG_ERROR, "reference picture missing during reorder\n"); memset(&sl->ref_list[list][index], 0, sizeof(sl->ref_list[0][0])); // FIXME } else { for (i = index; i + 1 < sl->ref_count[list]; i++) { if (sl->ref_list[list][i].parent && ref->long_ref == sl->ref_list[list][i].parent->long_ref && ref->pic_id == sl->ref_list[list][i].pic_id) break; } for (; i > index; i--) { sl->ref_list[list][i] = sl->ref_list[list][i - 1]; } ref_from_h264pic(&sl->ref_list[list][index], ref); if (FIELD_PICTURE(h)) { pic_as_field(&sl->ref_list[list][index], pic_structure); } } } } for (list = 0; list < sl->list_count; list++) { for (index = 0; index < sl->ref_count[list]; index++) { if (!sl->ref_list[list][index].parent) { av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture\n"); if (index == 0 || h->avctx->err_recognition & AV_EF_EXPLODE) return AVERROR_INVALIDDATA; else sl->ref_list[list][index] = sl->ref_list[list][index - 1]; } } } if (FRAME_MBAFF(h)) h264_fill_mbaff_ref_list(sl); return 0; } int ff_h264_decode_ref_pic_list_reordering(const H264Context *h, H264SliceContext *sl) { int list, index; sl->nb_ref_modifications[0] = 0; sl->nb_ref_modifications[1] = 0; for (list = 0; list < sl->list_count; list++) { if (!get_bits1(&sl->gb)) // ref_pic_list_modification_flag_l[01] continue; for (index = 0; ; index++) { unsigned int op = get_ue_golomb_31(&sl->gb); if (op == 3) break; if (index >= sl->ref_count[list]) { av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n"); return AVERROR_INVALIDDATA; } else if (op > 2) { av_log(h->avctx, AV_LOG_ERROR, "illegal modification_of_pic_nums_idc %u\n", op); return AVERROR_INVALIDDATA; } sl->ref_modifications[list][index].val = get_ue_golomb(&sl->gb); sl->ref_modifications[list][index].op = op; sl->nb_ref_modifications[list]++; } } return 0; } /** * Mark a picture as no longer needed for reference. The refmask * argument allows unreferencing of individual fields or the whole frame. * If the picture becomes entirely unreferenced, but is being held for * display purposes, it is marked as such. * @param refmask mask of fields to unreference; the mask is bitwise * anded with the reference marking of pic * @return non-zero if pic becomes entirely unreferenced (except possibly * for display purposes) zero if one of the fields remains in * reference */ static inline int unreference_pic(H264Context *h, H264Picture *pic, int refmask) { int i; if (pic->reference &= refmask) { return 0; } else { for(i = 0; h->delayed_pic[i]; i++) if(pic == h->delayed_pic[i]){ pic->reference = DELAYED_PIC_REF; break; } return 1; } } /** * Find a H264Picture in the short term reference list by frame number. * @param frame_num frame number to search for * @param idx the index into h->short_ref where returned picture is found * undefined if no picture found. * @return pointer to the found picture, or NULL if no pic with the provided * frame number is found */ static H264Picture *find_short(H264Context *h, int frame_num, int *idx) { int i; for (i = 0; i < h->short_ref_count; i++) { H264Picture *pic = h->short_ref[i]; if (h->avctx->debug & FF_DEBUG_MMCO) av_log(h->avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic); if (pic->frame_num == frame_num) { *idx = i; return pic; } } return NULL; } /** * Remove a picture from the short term reference list by its index in * that list. This does no checking on the provided index; it is assumed * to be valid. Other list entries are shifted down. * @param i index into h->short_ref of picture to remove. */ static void remove_short_at_index(H264Context *h, int i) { assert(i >= 0 && i < h->short_ref_count); h->short_ref[i] = NULL; if (--h->short_ref_count) memmove(&h->short_ref[i], &h->short_ref[i + 1], (h->short_ref_count - i) * sizeof(H264Picture*)); } /** * @return the removed picture or NULL if an error occurs */ static H264Picture *remove_short(H264Context *h, int frame_num, int ref_mask) { H264Picture *pic; int i; if (h->avctx->debug & FF_DEBUG_MMCO) av_log(h->avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count); pic = find_short(h, frame_num, &i); if (pic) { if (unreference_pic(h, pic, ref_mask)) remove_short_at_index(h, i); } return pic; } /** * Remove a picture from the long term reference list by its index in * that list. * @return the removed picture or NULL if an error occurs */ static H264Picture *remove_long(H264Context *h, int i, int ref_mask) { H264Picture *pic; pic = h->long_ref[i]; if (pic) { if (unreference_pic(h, pic, ref_mask)) { assert(h->long_ref[i]->long_ref == 1); h->long_ref[i]->long_ref = 0; h->long_ref[i] = NULL; h->long_ref_count--; } } return pic; } void ff_h264_remove_all_refs(H264Context *h) { int i; for (i = 0; i < 16; i++) { remove_long(h, i, 0); } assert(h->long_ref_count == 0); for (i = 0; i < h->short_ref_count; i++) { unreference_pic(h, h->short_ref[i], 0); h->short_ref[i] = NULL; } h->short_ref_count = 0; } static void generate_sliding_window_mmcos(H264Context *h) { MMCO *mmco = h->mmco; int nb_mmco = 0; assert(h->long_ref_count + h->short_ref_count <= h->ps.sps->ref_frame_count); if (h->short_ref_count && h->long_ref_count + h->short_ref_count == h->ps.sps->ref_frame_count && !(FIELD_PICTURE(h) && !h->first_field && h->cur_pic_ptr->reference)) { mmco[0].opcode = MMCO_SHORT2UNUSED; mmco[0].short_pic_num = h->short_ref[h->short_ref_count - 1]->frame_num; nb_mmco = 1; if (FIELD_PICTURE(h)) { mmco[0].short_pic_num *= 2; mmco[1].opcode = MMCO_SHORT2UNUSED; mmco[1].short_pic_num = mmco[0].short_pic_num + 1; nb_mmco = 2; } } h->nb_mmco = nb_mmco; } int ff_h264_execute_ref_pic_marking(H264Context *h) { MMCO *mmco = h->mmco; int mmco_count; int i, av_uninit(j); int current_ref_assigned = 0, err = 0; H264Picture *av_uninit(pic); if (!h->explicit_ref_marking) generate_sliding_window_mmcos(h); mmco_count = h->nb_mmco; 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 interesting 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->poc.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->ps.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->ps.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; } int ff_h264_decode_ref_pic_marking(const H264Context *h, H264SliceContext *sl, GetBitContext *gb) { int i; MMCO *mmco = sl->mmco; int nb_mmco = 0; if (h->nal_unit_type == NAL_IDR_SLICE) { // FIXME fields skip_bits1(gb); // broken_link if (get_bits1(gb)) { mmco[0].opcode = MMCO_LONG; mmco[0].long_arg = 0; nb_mmco = 1; } sl->explicit_ref_marking = 1; } else { sl->explicit_ref_marking = get_bits1(gb); if (sl->explicit_ref_marking) { for (i = 0; i < MAX_MMCO_COUNT; i++) { MMCOOpcode opcode = get_ue_golomb_31(gb); mmco[i].opcode = opcode; if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) { mmco[i].short_pic_num = (h->curr_pic_num - get_ue_golomb(gb) - 1) & (h->max_pic_num - 1); #if 0 if (mmco[i].short_pic_num >= h->short_ref_count || !h->short_ref[mmco[i].short_pic_num]) { av_log(s->avctx, AV_LOG_ERROR, "illegal short ref in memory management control " "operation %d\n", mmco); return -1; } #endif } if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED || opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) { unsigned int long_arg = get_ue_golomb_31(gb); if (long_arg >= 32 || (long_arg >= 16 && !(opcode == MMCO_SET_MAX_LONG && long_arg == 16) && !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE(h)))) { av_log(h->avctx, AV_LOG_ERROR, "illegal long ref in memory management control " "operation %d\n", opcode); return -1; } mmco[i].long_arg = long_arg; } if (opcode > (unsigned) MMCO_LONG) { av_log(h->avctx, AV_LOG_ERROR, "illegal memory management control operation %d\n", opcode); return -1; } if (opcode == MMCO_END) break; } nb_mmco = i; } } sl->nb_mmco = nb_mmco; return 0; }