| /* |
| * 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) { |
| #if HAVE_FAST_UNALIGNED |
| /* we check i < buf_size instead of i + 3 / 7 because it is |
| * simpler and there must be FF_INPUT_BUFFER_PADDING_SIZE |
| * bytes at the end. |
| */ |
| # if HAVE_FAST_64BIT |
| while (i < next_avc && |
| !((~*(const uint64_t *)(buf + i) & |
| (*(const uint64_t *)(buf + i) - 0x0101010101010101ULL)) & |
| 0x8080808080808080ULL)) |
| i += 8; |
| # else |
| while (i < next_avc && |
| !((~*(const uint32_t *)(buf + i) & |
| (*(const uint32_t *)(buf + i) - 0x01010101U)) & |
| 0x80808080U)) |
| i += 4; |
| # endif |
| #endif |
| for (; i < next_avc; i++) |
| if (!buf[i]) { |
| state = 2; |
| break; |
| } |
| } 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); |
| } |
| |
| /** |
| * 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; |
| 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; |
| h->sei_recovery_frame_cnt = -1; |
| h->sei_dpb_output_delay = 0; |
| h->sei_cpb_removal_delay = -1; |
| h->sei_buffering_period_present = 0; |
| |
| 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 (src_length > 20) |
| src_length = 20; |
| 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); |
| |
| 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); |
| } |
| |
| ff_init_poc(h, field_poc, NULL); |
| |
| 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; |
| 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, |
| }; |
