/* * H.26L/H.264/AVC/JVT/14496-10/... parser * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * H.264 / AVC / MPEG4 part10 parser. * @author Michael Niedermayer <michaelni@gmx.at> */ #define UNCHECKED_BITSTREAM_READER 1 #include "libavutil/attributes.h" #include "parser.h" #include "h264data.h" #include "golomb.h" #include "internal.h" static int h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size) { int i, j; uint32_t state; ParseContext *pc = &h->parse_context; int next_avc= h->is_avc ? 0 : buf_size; // mb_addr= pc->mb_addr - 1; state = pc->state; if (state > 13) state = 7; if (h->is_avc && !h->nal_length_size) av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal length size invalid\n"); for (i = 0; i < buf_size; i++) { if (i >= next_avc) { int nalsize = 0; i = next_avc; for (j = 0; j < h->nal_length_size; j++) nalsize = (nalsize << 8) | buf[i++]; if (nalsize <= 0 || nalsize > buf_size - i) { av_log(h->avctx, AV_LOG_ERROR, "AVC-parser: nal size %d remaining %d\n", nalsize, buf_size - i); return buf_size; } next_avc = i + nalsize; state = 5; } if (state == 7) { i += h->h264dsp.h264_find_start_code_candidate(buf + i, next_avc - i); if (i < next_avc) state = 2; } else if (state <= 2) { if (buf[i] == 1) state ^= 5; // 2->7, 1->4, 0->5 else if (buf[i]) state = 7; else state >>= 1; // 2->1, 1->0, 0->0 } else if (state <= 5) { int v = buf[i] & 0x1F; if (v == 6 || v == 7 || v == 8 || v == 9) { if (pc->frame_start_found) { i++; goto found; } } else if (v == 1 || v == 2 || v == 5) { state += 8; continue; } state = 7; } else { h->parse_history[h->parse_history_count++]= buf[i]; if (h->parse_history_count>3) { unsigned int mb, last_mb= h->parse_last_mb; GetBitContext gb; init_get_bits(&gb, h->parse_history, 8*h->parse_history_count); h->parse_history_count=0; mb= get_ue_golomb_long(&gb); last_mb= h->parse_last_mb; h->parse_last_mb= mb; if (pc->frame_start_found) { if (mb <= last_mb) goto found; } else pc->frame_start_found = 1; state = 7; } } } pc->state = state; if (h->is_avc) return next_avc; return END_NOT_FOUND; found: pc->state = 7; pc->frame_start_found = 0; if (h->is_avc) return next_avc; return i - (state & 5) - 3 * (state > 7); } static int scan_mmco_reset(AVCodecParserContext *s) { H264Context *h = s->priv_data; h->slice_type_nos = s->pict_type & 3; if (h->pps.redundant_pic_cnt_present) get_ue_golomb(&h->gb); // redundant_pic_count if (ff_set_ref_count(h) < 0) return AVERROR_INVALIDDATA; if (h->slice_type_nos != AV_PICTURE_TYPE_I) { int list; for (list = 0; list < h->list_count; list++) { if (get_bits1(&h->gb)) { int index; for (index = 0; ; index++) { unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(&h->gb); if (reordering_of_pic_nums_idc < 3) get_ue_golomb(&h->gb); else if (reordering_of_pic_nums_idc > 3) { av_log(h->avctx, AV_LOG_ERROR, "illegal reordering_of_pic_nums_idc %d\n", reordering_of_pic_nums_idc); return AVERROR_INVALIDDATA; } else break; if (index >= h->ref_count[list]) { av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n"); return AVERROR_INVALIDDATA; } } } } } if ((h->pps.weighted_pred && h->slice_type_nos == AV_PICTURE_TYPE_P) || (h->pps.weighted_bipred_idc == 1 && h->slice_type_nos == AV_PICTURE_TYPE_B)) ff_pred_weight_table(h); if (get_bits1(&h->gb)) { // adaptive_ref_pic_marking_mode_flag int i; for (i = 0; i < MAX_MMCO_COUNT; i++) { MMCOOpcode opcode = get_ue_golomb_31(&h->gb); if (opcode > (unsigned) MMCO_LONG) { av_log(h->avctx, AV_LOG_ERROR, "illegal memory management control operation %d\n", opcode); return AVERROR_INVALIDDATA; } if (opcode == MMCO_END) return 0; else if (opcode == MMCO_RESET) return 1; if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) get_ue_golomb(&h->gb); if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED || opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) get_ue_golomb_31(&h->gb); } } return 0; } /** * Parse NAL units of found picture and decode some basic information. * * @param s parser context. * @param avctx codec context. * @param buf buffer with field/frame data. * @param buf_size size of the buffer. */ static inline int parse_nal_units(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t *buf, int buf_size) { H264Context *h = s->priv_data; const uint8_t *buf_end = buf + buf_size; unsigned int pps_id; unsigned int slice_type; int state = -1, got_reset = 0; const uint8_t *ptr; int q264 = buf_size >=4 && !memcmp("Q264", buf, 4); int field_poc[2]; /* set some sane default values */ s->pict_type = AV_PICTURE_TYPE_I; s->key_frame = 0; s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN; h->avctx = avctx; ff_h264_reset_sei(h); h->sei_fpa.frame_packing_arrangement_cancel_flag = -1; if (!buf_size) return 0; for (;;) { int src_length, dst_length, consumed, nalsize = 0; if (h->is_avc) { int i; if (h->nal_length_size >= buf_end - buf) break; nalsize = 0; for (i = 0; i < h->nal_length_size; i++) nalsize = (nalsize << 8) | *buf++; if (nalsize <= 0 || nalsize > buf_end - buf) { av_log(h->avctx, AV_LOG_ERROR, "AVC: nal size %d\n", nalsize); break; } src_length = nalsize; } else { buf = avpriv_find_start_code(buf, buf_end, &state); if (buf >= buf_end) break; --buf; src_length = buf_end - buf; } switch (state & 0x1f) { case NAL_SLICE: case NAL_IDR_SLICE: // Do not walk the whole buffer just to decode slice header if ((state & 0x1f) == NAL_IDR_SLICE || ((state >> 5) & 0x3) == 0) { /* IDR or disposable slice * No need to decode many bytes because MMCOs shall not be present. */ if (src_length > 60) src_length = 60; } else { /* To decode up to MMCOs */ if (src_length > 1000) src_length = 1000; } break; } ptr = ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length); if (ptr == NULL || dst_length < 0) break; init_get_bits(&h->gb, ptr, 8 * dst_length); switch (h->nal_unit_type) { case NAL_SPS: ff_h264_decode_seq_parameter_set(h); break; case NAL_PPS: ff_h264_decode_picture_parameter_set(h, h->gb.size_in_bits); break; case NAL_SEI: ff_h264_decode_sei(h); break; case NAL_IDR_SLICE: s->key_frame = 1; h->prev_frame_num = 0; h->prev_frame_num_offset = 0; h->prev_poc_msb = h->prev_poc_lsb = 0; /* fall through */ case NAL_SLICE: get_ue_golomb_long(&h->gb); // skip first_mb_in_slice slice_type = get_ue_golomb_31(&h->gb); s->pict_type = golomb_to_pict_type[slice_type % 5]; if (h->sei_recovery_frame_cnt >= 0) { /* key frame, since recovery_frame_cnt is set */ s->key_frame = 1; } pps_id = get_ue_golomb(&h->gb); if (pps_id >= MAX_PPS_COUNT) { av_log(h->avctx, AV_LOG_ERROR, "pps_id out of range\n"); return -1; } if (!h->pps_buffers[pps_id]) { av_log(h->avctx, AV_LOG_ERROR, "non-existing PPS referenced\n"); return -1; } h->pps = *h->pps_buffers[pps_id]; if (!h->sps_buffers[h->pps.sps_id]) { av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS referenced\n"); return -1; } h->sps = *h->sps_buffers[h->pps.sps_id]; h->frame_num = get_bits(&h->gb, h->sps.log2_max_frame_num); if(h->sps.ref_frame_count <= 1 && h->pps.ref_count[0] <= 1 && s->pict_type == AV_PICTURE_TYPE_I) s->key_frame = 1; avctx->profile = ff_h264_get_profile(&h->sps); avctx->level = h->sps.level_idc; if (h->sps.frame_mbs_only_flag) { h->picture_structure = PICT_FRAME; } else { if (get_bits1(&h->gb)) { // field_pic_flag h->picture_structure = PICT_TOP_FIELD + get_bits1(&h->gb); // bottom_field_flag } else { h->picture_structure = PICT_FRAME; } } if (h->nal_unit_type == NAL_IDR_SLICE) get_ue_golomb(&h->gb); /* idr_pic_id */ if (h->sps.poc_type == 0) { h->poc_lsb = get_bits(&h->gb, h->sps.log2_max_poc_lsb); if (h->pps.pic_order_present == 1 && h->picture_structure == PICT_FRAME) h->delta_poc_bottom = get_se_golomb(&h->gb); } if (h->sps.poc_type == 1 && !h->sps.delta_pic_order_always_zero_flag) { h->delta_poc[0] = get_se_golomb(&h->gb); if (h->pps.pic_order_present == 1 && h->picture_structure == PICT_FRAME) h->delta_poc[1] = get_se_golomb(&h->gb); } /* Decode POC of this picture. * The prev_ values needed for decoding POC of the next picture are not set here. */ field_poc[0] = field_poc[1] = INT_MAX; ff_init_poc(h, field_poc, &s->output_picture_number); /* Continue parsing to check if MMCO_RESET is present. * FIXME: MMCO_RESET could appear in non-first slice. * Maybe, we should parse all undisposable non-IDR slice of this * picture until encountering MMCO_RESET in a slice of it. */ if (h->nal_ref_idc && h->nal_unit_type != NAL_IDR_SLICE) { got_reset = scan_mmco_reset(s); if (got_reset < 0) return got_reset; } /* Set up the prev_ values for decoding POC of the next picture. */ h->prev_frame_num = got_reset ? 0 : h->frame_num; h->prev_frame_num_offset = got_reset ? 0 : h->frame_num_offset; if (h->nal_ref_idc != 0) { if (!got_reset) { h->prev_poc_msb = h->poc_msb; h->prev_poc_lsb = h->poc_lsb; } else { h->prev_poc_msb = 0; h->prev_poc_lsb = h->picture_structure == PICT_BOTTOM_FIELD ? 0 : field_poc[0]; } } if (h->sps.pic_struct_present_flag) { switch (h->sei_pic_struct) { case SEI_PIC_STRUCT_TOP_FIELD: case SEI_PIC_STRUCT_BOTTOM_FIELD: s->repeat_pict = 0; break; case SEI_PIC_STRUCT_FRAME: case SEI_PIC_STRUCT_TOP_BOTTOM: case SEI_PIC_STRUCT_BOTTOM_TOP: s->repeat_pict = 1; break; case SEI_PIC_STRUCT_TOP_BOTTOM_TOP: case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM: s->repeat_pict = 2; break; case SEI_PIC_STRUCT_FRAME_DOUBLING: s->repeat_pict = 3; break; case SEI_PIC_STRUCT_FRAME_TRIPLING: s->repeat_pict = 5; break; default: s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0; break; } } else { s->repeat_pict = h->picture_structure == PICT_FRAME ? 1 : 0; } if (h->picture_structure == PICT_FRAME) { s->picture_structure = AV_PICTURE_STRUCTURE_FRAME; if (h->sps.pic_struct_present_flag) { switch (h->sei_pic_struct) { case SEI_PIC_STRUCT_TOP_BOTTOM: case SEI_PIC_STRUCT_TOP_BOTTOM_TOP: s->field_order = AV_FIELD_TT; break; case SEI_PIC_STRUCT_BOTTOM_TOP: case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM: s->field_order = AV_FIELD_BB; break; default: s->field_order = AV_FIELD_PROGRESSIVE; break; } } else { if (field_poc[0] < field_poc[1]) s->field_order = AV_FIELD_TT; else if (field_poc[0] > field_poc[1]) s->field_order = AV_FIELD_BB; else s->field_order = AV_FIELD_PROGRESSIVE; } } else { if (h->picture_structure == PICT_TOP_FIELD) s->picture_structure = AV_PICTURE_STRUCTURE_TOP_FIELD; else s->picture_structure = AV_PICTURE_STRUCTURE_BOTTOM_FIELD; s->field_order = AV_FIELD_UNKNOWN; } return 0; /* no need to evaluate the rest */ } buf += h->is_avc ? nalsize : consumed; } if (q264) return 0; /* didn't find a picture! */ av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size); return -1; } static int h264_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size) { H264Context *h = s->priv_data; ParseContext *pc = &h->parse_context; int next; if (!h->got_first) { h->got_first = 1; if (avctx->extradata_size) { h->avctx = avctx; // must be done like in decoder, otherwise opening the parser, // letting it create extradata and then closing and opening again // will cause has_b_frames to be always set. // Note that estimate_timings_from_pts does exactly this. if (!avctx->has_b_frames) h->low_delay = 1; ff_h264_decode_extradata(h, avctx->extradata, avctx->extradata_size); } } if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { next = buf_size; } else { next = h264_find_frame_end(h, buf, buf_size); if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { *poutbuf = NULL; *poutbuf_size = 0; return buf_size; } if (next < 0 && next != END_NOT_FOUND) { av_assert1(pc->last_index + next >= 0); h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); // update state } } parse_nal_units(s, avctx, buf, buf_size); if (h->sei_cpb_removal_delay >= 0) { s->dts_sync_point = h->sei_buffering_period_present; s->dts_ref_dts_delta = h->sei_cpb_removal_delay; s->pts_dts_delta = h->sei_dpb_output_delay; } else { s->dts_sync_point = INT_MIN; s->dts_ref_dts_delta = INT_MIN; s->pts_dts_delta = INT_MIN; } if (s->flags & PARSER_FLAG_ONCE) { s->flags &= PARSER_FLAG_COMPLETE_FRAMES; } *poutbuf = buf; *poutbuf_size = buf_size; return next; } static int h264_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size) { int i; uint32_t state = -1; int has_sps = 0; for (i = 0; i <= buf_size; i++) { if ((state & 0xFFFFFF1F) == 0x107) has_sps = 1; /* if ((state&0xFFFFFF1F) == 0x101 || * (state&0xFFFFFF1F) == 0x102 || * (state&0xFFFFFF1F) == 0x105) { * } */ if ((state & 0xFFFFFF00) == 0x100 && (state & 0xFFFFFF1F) != 0x107 && (state & 0xFFFFFF1F) != 0x108 && (state & 0xFFFFFF1F) != 0x109) { if (has_sps) { while (i > 4 && buf[i - 5] == 0) i--; return i - 4; } } if (i < buf_size) state = (state << 8) | buf[i]; } return 0; } static void close(AVCodecParserContext *s) { H264Context *h = s->priv_data; ParseContext *pc = &h->parse_context; av_free(pc->buffer); ff_h264_free_context(h); } static av_cold int init(AVCodecParserContext *s) { H264Context *h = s->priv_data; h->thread_context[0] = h; h->slice_context_count = 1; ff_h264dsp_init(&h->h264dsp, 8, 1); return 0; } AVCodecParser ff_h264_parser = { .codec_ids = { AV_CODEC_ID_H264 }, .priv_data_size = sizeof(H264Context), .parser_init = init, .parser_parse = h264_parse, .parser_close = close, .split = h264_split, };