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Parse NAL units in H264 parser.
Patch by Ivan Schreter, schreter gmx net Originally committed as revision 17488 to svn://svn.ffmpeg.org/ffmpeg/trunk
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@ -27,6 +27,8 @@
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#include "parser.h"
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#include "parser.h"
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#include "h264_parser.h"
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#include "h264_parser.h"
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#include "h264data.h"
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#include "golomb.h"
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#include <assert.h>
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#include <assert.h>
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@ -96,6 +98,73 @@ found:
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return i-(state&5);
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return i-(state&5);
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}
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}
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/*!
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* Parse NAL units of found picture and decode some basic information.
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*
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* @param s parser context.
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* @param avctx codec context.
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* @param buf buffer with field/frame data.
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* @param buf_size size of the buffer.
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*/
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static inline int parse_nal_units(AVCodecParserContext *s,
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AVCodecContext *avctx,
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const uint8_t *buf, int buf_size)
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{
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H264Context *h = s->priv_data;
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const uint8_t *buf_end = buf + buf_size;
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unsigned int slice_type;
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int state;
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const uint8_t *ptr;
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/* set some sane default values */
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s->pict_type = FF_I_TYPE;
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h->s.avctx= avctx;
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for(;;) {
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int src_length, dst_length, consumed;
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buf = ff_find_start_code(buf, buf_end, &state);
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if(buf >= buf_end)
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break;
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--buf;
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src_length = buf_end - buf;
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switch (state & 0x1f) {
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case NAL_SLICE:
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case NAL_IDR_SLICE:
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// Do not walk the whole buffer just to decode slice header
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if (src_length > 20)
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src_length = 20;
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break;
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}
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ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
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if (ptr==NULL || dst_length < 0)
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break;
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init_get_bits(&h->s.gb, ptr, 8*dst_length);
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switch(h->nal_unit_type) {
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case NAL_SPS:
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ff_h264_decode_seq_parameter_set(h);
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break;
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case NAL_PPS:
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ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
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break;
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case NAL_SEI:
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ff_h264_decode_sei(h);
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break;
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case NAL_IDR_SLICE:
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case NAL_SLICE:
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get_ue_golomb(&h->s.gb); // skip first_mb_in_slice
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slice_type = get_ue_golomb_31(&h->s.gb);
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s->pict_type = golomb_to_pict_type[slice_type % 5];
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return 0; /* no need to evaluate the rest */
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}
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buf += consumed;
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}
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/* didn't find a picture! */
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av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
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return -1;
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}
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static int h264_parse(AVCodecParserContext *s,
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static int h264_parse(AVCodecParserContext *s,
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AVCodecContext *avctx,
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AVCodecContext *avctx,
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const uint8_t **poutbuf, int *poutbuf_size,
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const uint8_t **poutbuf, int *poutbuf_size,
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@ -120,6 +189,8 @@ static int h264_parse(AVCodecParserContext *s,
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assert(pc->last_index + next >= 0 );
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assert(pc->last_index + next >= 0 );
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ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
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ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
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}
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}
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parse_nal_units(s, avctx, buf, buf_size);
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}
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}
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*poutbuf = buf;
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*poutbuf = buf;
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