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ffmpeg/libavcodec/hevc_parser.c

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/*
* HEVC Annex B format parser
*
* Copyright (C) 2012 - 2013 Guillaume Martres
*
* 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
*/
#include "libavutil/common.h"
#include "golomb.h"
#include "hevc.h"
#include "parser.h"
#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
#define IS_IRAP_NAL(nal) (nal->type >= 16 && nal->type <= 23)
#define ADVANCED_PARSER CONFIG_HEVC_DECODER
typedef struct HEVCParserContext {
ParseContext pc;
HEVCPacket pkt;
HEVCParamSets ps;
int parsed_extradata;
#if ADVANCED_PARSER
HEVCContext h;
#endif
} HEVCParserContext;
#if !ADVANCED_PARSER
static int hevc_parse_slice_header(AVCodecParserContext *s, HEVCNAL *nal,
AVCodecContext *avctx)
{
HEVCParserContext *ctx = s->priv_data;
GetBitContext *gb = &nal->gb;
HEVCPPS *pps;
HEVCSPS *sps;
unsigned int pps_id;
get_bits1(gb); // first slice in pic
if (IS_IRAP_NAL(nal))
get_bits1(gb); // no output of prior pics
pps_id = get_ue_golomb_long(gb);
if (pps_id >= MAX_PPS_COUNT || !ctx->ps.pps_list[pps_id]) {
av_log(avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", pps_id);
return AVERROR_INVALIDDATA;
}
pps = (HEVCPPS*)ctx->ps.pps_list[pps_id]->data;
sps = (HEVCSPS*)ctx->ps.sps_list[pps->sps_id]->data;
/* export the stream parameters */
s->coded_width = sps->width;
s->coded_height = sps->height;
s->width = sps->output_width;
s->height = sps->output_height;
s->format = sps->pix_fmt;
avctx->profile = sps->ptl.general_ptl.profile_idc;
avctx->level = sps->ptl.general_ptl.level_idc;
/* ignore the rest for now*/
return 0;
}
static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
int buf_size, AVCodecContext *avctx)
{
HEVCParserContext *ctx = s->priv_data;
int ret, i;
ret = ff_hevc_split_packet(NULL, &ctx->pkt, buf, buf_size, avctx, 0, 0);
if (ret < 0)
return ret;
for (i = 0; i < ctx->pkt.nb_nals; i++) {
HEVCNAL *nal = &ctx->pkt.nals[i];
/* ignore everything except parameter sets and VCL NALUs */
switch (nal->type) {
case NAL_VPS: ff_hevc_decode_nal_vps(&nal->gb, avctx, &ctx->ps); break;
case NAL_SPS: ff_hevc_decode_nal_sps(&nal->gb, avctx, &ctx->ps, 1); break;
case NAL_PPS: ff_hevc_decode_nal_pps(&nal->gb, avctx, &ctx->ps); break;
case NAL_TRAIL_R:
case NAL_TRAIL_N:
case NAL_TSA_N:
case NAL_TSA_R:
case NAL_STSA_N:
case NAL_STSA_R:
case NAL_BLA_W_LP:
case NAL_BLA_W_RADL:
case NAL_BLA_N_LP:
case NAL_IDR_W_RADL:
case NAL_IDR_N_LP:
case NAL_CRA_NUT:
case NAL_RADL_N:
case NAL_RADL_R:
case NAL_RASL_N:
case NAL_RASL_R:
if (buf == avctx->extradata) {
av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit: %d\n", nal->type);
return AVERROR_INVALIDDATA;
}
hevc_parse_slice_header(s, nal, avctx);
break;
}
}
return 0;
}
#endif
/**
* Find the end of the current frame in the bitstream.
* @return the position of the first byte of the next frame, or END_NOT_FOUND
*/
static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
int buf_size)
{
int i;
ParseContext *pc = s->priv_data;
for (i = 0; i < buf_size; i++) {
int nut;
pc->state64 = (pc->state64 << 8) | buf[i];
if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
continue;
nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
// Beginning of access unit
if ((nut >= NAL_VPS && nut <= NAL_AUD) || nut == NAL_SEI_PREFIX ||
(nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
if (pc->frame_start_found) {
pc->frame_start_found = 0;
return i - 5;
}
} else if (nut <= NAL_RASL_R ||
(nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT)) {
int first_slice_segment_in_pic_flag = buf[i] >> 7;
if (first_slice_segment_in_pic_flag) {
if (!pc->frame_start_found) {
pc->frame_start_found = 1;
} else { // First slice of next frame found
pc->frame_start_found = 0;
return i - 5;
}
}
}
}
return END_NOT_FOUND;
}
#if ADVANCED_PARSER
/**
* 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, const uint8_t *buf,
int buf_size, AVCodecContext *avctx)
{
HEVCParserContext *ctx = s->priv_data;
HEVCContext *h = &ctx->h;
GetBitContext *gb;
SliceHeader *sh = &h->sh;
HEVCParamSets *ps = &h->ps;
HEVCPacket *pkt = &ctx->pkt;
const uint8_t *buf_end = buf + buf_size;
int state = -1, i;
HEVCNAL *nal;
int is_global = buf == avctx->extradata;
if (!h->HEVClc)
h->HEVClc = av_mallocz(sizeof(HEVCLocalContext));
if (!h->HEVClc)
return AVERROR(ENOMEM);
gb = &h->HEVClc->gb;
/* 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;
if (!buf_size)
return 0;
if (pkt->nals_allocated < 1) {
HEVCNAL *tmp = av_realloc_array(pkt->nals, 1, sizeof(*tmp));
if (!tmp)
return AVERROR(ENOMEM);
pkt->nals = tmp;
memset(pkt->nals, 0, sizeof(*tmp));
pkt->nals_allocated = 1;
}
nal = &pkt->nals[0];
for (;;) {
int src_length, consumed;
int ret;
buf = avpriv_find_start_code(buf, buf_end, &state);
if (--buf + 2 >= buf_end)
break;
src_length = buf_end - buf;
h->nal_unit_type = (*buf >> 1) & 0x3f;
h->temporal_id = (*(buf + 1) & 0x07) - 1;
if (h->nal_unit_type <= NAL_CRA_NUT) {
// Do not walk the whole buffer just to decode slice segment header
if (src_length > 20)
src_length = 20;
}
consumed = ff_hevc_extract_rbsp(NULL, buf, src_length, nal);
if (consumed < 0)
return consumed;
ret = init_get_bits8(gb, nal->data + 2, nal->size);
if (ret < 0)
return ret;
switch (h->nal_unit_type) {
case NAL_VPS:
ff_hevc_decode_nal_vps(gb, avctx, ps);
break;
case NAL_SPS:
ff_hevc_decode_nal_sps(gb, avctx, ps, 1);
break;
case NAL_PPS:
ff_hevc_decode_nal_pps(gb, avctx, ps);
break;
case NAL_SEI_PREFIX:
case NAL_SEI_SUFFIX:
ff_hevc_decode_nal_sei(h);
break;
case NAL_TRAIL_N:
case NAL_TRAIL_R:
case NAL_TSA_N:
case NAL_TSA_R:
case NAL_STSA_N:
case NAL_STSA_R:
case NAL_RADL_N:
case NAL_RADL_R:
case NAL_RASL_N:
case NAL_RASL_R:
case NAL_BLA_W_LP:
case NAL_BLA_W_RADL:
case NAL_BLA_N_LP:
case NAL_IDR_W_RADL:
case NAL_IDR_N_LP:
case NAL_CRA_NUT:
if (is_global) {
av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit: %d\n", h->nal_unit_type);
return AVERROR_INVALIDDATA;
}
sh->first_slice_in_pic_flag = get_bits1(gb);
s->picture_structure = h->picture_struct;
s->field_order = h->picture_struct;
if (IS_IRAP(h)) {
s->key_frame = 1;
sh->no_output_of_prior_pics_flag = get_bits1(gb);
}
sh->pps_id = get_ue_golomb(gb);
if (sh->pps_id >= MAX_PPS_COUNT || !ps->pps_list[sh->pps_id]) {
av_log(avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", sh->pps_id);
return AVERROR_INVALIDDATA;
}
ps->pps = (HEVCPPS*)ps->pps_list[sh->pps_id]->data;
if (ps->pps->sps_id >= MAX_SPS_COUNT || !ps->sps_list[ps->pps->sps_id]) {
av_log(avctx, AV_LOG_ERROR, "SPS id out of range: %d\n", ps->pps->sps_id);
return AVERROR_INVALIDDATA;
}
if (ps->sps != (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data) {
ps->sps = (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data;
ps->vps = (HEVCVPS*)ps->vps_list[ps->sps->vps_id]->data;
}
if (!sh->first_slice_in_pic_flag) {
int slice_address_length;
if (ps->pps->dependent_slice_segments_enabled_flag)
sh->dependent_slice_segment_flag = get_bits1(gb);
else
sh->dependent_slice_segment_flag = 0;
slice_address_length = av_ceil_log2_c(ps->sps->ctb_width *
ps->sps->ctb_height);
sh->slice_segment_addr = slice_address_length ? get_bits(gb, slice_address_length) : 0;
if (sh->slice_segment_addr >= ps->sps->ctb_width * ps->sps->ctb_height) {
av_log(avctx, AV_LOG_ERROR, "Invalid slice segment address: %u.\n",
sh->slice_segment_addr);
return AVERROR_INVALIDDATA;
}
} else
sh->dependent_slice_segment_flag = 0;
if (sh->dependent_slice_segment_flag)
break;
for (i = 0; i < ps->pps->num_extra_slice_header_bits; i++)
skip_bits(gb, 1); // slice_reserved_undetermined_flag[]
sh->slice_type = get_ue_golomb(gb);
if (!(sh->slice_type == I_SLICE || sh->slice_type == P_SLICE ||
sh->slice_type == B_SLICE)) {
av_log(avctx, AV_LOG_ERROR, "Unknown slice type: %d.\n",
sh->slice_type);
return AVERROR_INVALIDDATA;
}
s->pict_type = sh->slice_type == B_SLICE ? AV_PICTURE_TYPE_B :
sh->slice_type == P_SLICE ? AV_PICTURE_TYPE_P :
AV_PICTURE_TYPE_I;
if (ps->pps->output_flag_present_flag)
sh->pic_output_flag = get_bits1(gb);
if (ps->sps->separate_colour_plane_flag)
sh->colour_plane_id = get_bits(gb, 2);
if (!IS_IDR(h)) {
sh->pic_order_cnt_lsb = get_bits(gb, ps->sps->log2_max_poc_lsb);
s->output_picture_number = h->poc = ff_hevc_compute_poc(h, sh->pic_order_cnt_lsb);
} else
s->output_picture_number = h->poc = 0;
if (h->temporal_id == 0 &&
h->nal_unit_type != NAL_TRAIL_N &&
h->nal_unit_type != NAL_TSA_N &&
h->nal_unit_type != NAL_STSA_N &&
h->nal_unit_type != NAL_RADL_N &&
h->nal_unit_type != NAL_RASL_N &&
h->nal_unit_type != NAL_RADL_R &&
h->nal_unit_type != NAL_RASL_R)
h->pocTid0 = h->poc;
return 0; /* no need to evaluate the rest */
}
buf += consumed;
}
/* didn't find a picture! */
if (!is_global)
av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit\n");
return -1;
}
#endif
static int hevc_parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
int next;
HEVCParserContext *ctx = s->priv_data;
ParseContext *pc = &ctx->pc;
if (avctx->extradata && !ctx->parsed_extradata) {
parse_nal_units(s, avctx->extradata, avctx->extradata_size, avctx);
ctx->parsed_extradata = 1;
}
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
next = hevc_find_frame_end(s, buf, buf_size);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
parse_nal_units(s, buf, buf_size, avctx);
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
// Split after the parameter sets at the beginning of the stream if they exist.
static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
{
const uint8_t *ptr = buf, *end = buf + buf_size;
uint32_t state = -1;
int has_vps = 0;
int has_sps = 0;
int has_pps = 0;
int nut;
while (ptr < end) {
ptr = avpriv_find_start_code(ptr, end, &state);
if ((state >> 8) != START_CODE)
break;
nut = (state >> 1) & 0x3F;
if (nut == NAL_VPS)
has_vps = 1;
else if (nut == NAL_SPS)
has_sps = 1;
else if (nut == NAL_PPS)
has_pps = 1;
else if ((nut != NAL_SEI_PREFIX || has_pps) &&
nut != NAL_AUD) {
if (has_vps && has_sps) {
while (ptr - 4 > buf && ptr[-5] == 0)
ptr--;
return ptr - 4 - buf;
}
}
}
return 0;
}
static void hevc_parser_close(AVCodecParserContext *s)
{
HEVCParserContext *ctx = s->priv_data;
int i;
#if ADVANCED_PARSER
HEVCContext *h = &ctx->h;
for (i = 0; i < FF_ARRAY_ELEMS(h->ps.vps_list); i++)
av_buffer_unref(&h->ps.vps_list[i]);
for (i = 0; i < FF_ARRAY_ELEMS(h->ps.sps_list); i++)
av_buffer_unref(&h->ps.sps_list[i]);
for (i = 0; i < FF_ARRAY_ELEMS(h->ps.pps_list); i++)
av_buffer_unref(&h->ps.pps_list[i]);
h->ps.sps = NULL;
av_freep(&h->HEVClc);
#endif
for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.vps_list); i++)
av_buffer_unref(&ctx->ps.vps_list[i]);
for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.sps_list); i++)
av_buffer_unref(&ctx->ps.sps_list[i]);
for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.pps_list); i++)
av_buffer_unref(&ctx->ps.pps_list[i]);
ctx->ps.sps = NULL;
for (i = 0; i < ctx->pkt.nals_allocated; i++) {
av_freep(&ctx->pkt.nals[i].rbsp_buffer);
av_freep(&ctx->pkt.nals[i].skipped_bytes_pos);
}
av_freep(&ctx->pkt.nals);
ctx->pkt.nals_allocated = 0;
av_freep(&ctx->pc.buffer);
}
AVCodecParser ff_hevc_parser = {
.codec_ids = { AV_CODEC_ID_HEVC },
.priv_data_size = sizeof(HEVCParserContext),
.parser_parse = hevc_parse,
.parser_close = hevc_parser_close,
.split = hevc_split,
};
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