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h264: Implement decoding of picture timing SEI message.

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Now correct values are propagated to interlaced_frame, top_field_first
and repeat_pict in AVFrame structure.

patch by ffdshow tryouts

Originally committed as revision 15773 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Andreas Öman 16 years ago
parent 9f0a705d46
commit b09a7c05f6
3 changed files with 144 additions and 13 deletions
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  1. 127
      libavcodec/h264.c
  2. 26
      libavcodec/h264.h
  3. 4
      libavcodec/h264data.h

127
libavcodec/h264.c
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@ -6803,6 +6803,53 @@ static int decode_slice(struct AVCodecContext *avctx, H264Context *h){
return -1; //not reached
}
static int decode_picture_timing(H264Context *h){
MpegEncContext * const s = &h->s;
if(h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag){
skip_bits(&s->gb, h->sps.cpb_removal_delay_length); /* cpb_removal_delay */
skip_bits(&s->gb, h->sps.dpb_output_delay_length); /* dpb_output_delay */
}
if(h->sps.pic_struct_present_flag){
unsigned int i, num_clock_ts;
h->sei_pic_struct = get_bits(&s->gb, 4);
if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
return -1;
num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
for (i = 0 ; i < num_clock_ts ; i++){
if(get_bits(&s->gb, 1)){ /* clock_timestamp_flag */
unsigned int full_timestamp_flag;
skip_bits(&s->gb, 2); /* ct_type */
skip_bits(&s->gb, 1); /* nuit_field_based_flag */
skip_bits(&s->gb, 5); /* counting_type */
full_timestamp_flag = get_bits(&s->gb, 1);
skip_bits(&s->gb, 1); /* discontinuity_flag */
skip_bits(&s->gb, 1); /* cnt_dropped_flag */
skip_bits(&s->gb, 8); /* n_frames */
if(full_timestamp_flag){
skip_bits(&s->gb, 6); /* seconds_value 0..59 */
skip_bits(&s->gb, 6); /* minutes_value 0..59 */
skip_bits(&s->gb, 5); /* hours_value 0..23 */
}else{
if(get_bits(&s->gb, 1)){ /* seconds_flag */
skip_bits(&s->gb, 6); /* seconds_value range 0..59 */
if(get_bits(&s->gb, 1)){ /* minutes_flag */
skip_bits(&s->gb, 6); /* minutes_value 0..59 */
if(get_bits(&s->gb, 1)) /* hours_flag */
skip_bits(&s->gb, 5); /* hours_value 0..23 */
}
}
}
if(h->sps.time_offset_length > 0)
skip_bits(&s->gb, h->sps.time_offset_length); /* time_offset */
}
}
}
return 0;
}
static int decode_unregistered_user_data(H264Context *h, int size){
MpegEncContext * const s = &h->s;
uint8_t user_data[16+256];
@ -6846,6 +6893,10 @@ static int decode_sei(H264Context *h){
}while(get_bits(&s->gb, 8) == 255);
switch(type){
case 1: // Picture timing SEI
if(decode_picture_timing(h) < 0)
return -1;
break;
case 5:
if(decode_unregistered_user_data(h, size) < 0)
return -1;
@ -6873,16 +6924,15 @@ static inline void decode_hrd_parameters(H264Context *h, SPS *sps){
get_bits1(&s->gb); /* cbr_flag */
}
get_bits(&s->gb, 5); /* initial_cpb_removal_delay_length_minus1 */
get_bits(&s->gb, 5); /* cpb_removal_delay_length_minus1 */
get_bits(&s->gb, 5); /* dpb_output_delay_length_minus1 */
get_bits(&s->gb, 5); /* time_offset_length */
sps->cpb_removal_delay_length = get_bits(&s->gb, 5) + 1;
sps->dpb_output_delay_length = get_bits(&s->gb, 5) + 1;
sps->time_offset_length = get_bits(&s->gb, 5);
}
static inline int decode_vui_parameters(H264Context *h, SPS *sps){
MpegEncContext * const s = &h->s;
int aspect_ratio_info_present_flag;
unsigned int aspect_ratio_idc;
int nal_hrd_parameters_present_flag, vcl_hrd_parameters_present_flag;
aspect_ratio_info_present_flag= get_bits1(&s->gb);
@ -6929,15 +6979,15 @@ static inline int decode_vui_parameters(H264Context *h, SPS *sps){
sps->fixed_frame_rate_flag = get_bits1(&s->gb);
}
nal_hrd_parameters_present_flag = get_bits1(&s->gb);
if(nal_hrd_parameters_present_flag)
sps->nal_hrd_parameters_present_flag = get_bits1(&s->gb);
if(sps->nal_hrd_parameters_present_flag)
decode_hrd_parameters(h, sps);
vcl_hrd_parameters_present_flag = get_bits1(&s->gb);
if(vcl_hrd_parameters_present_flag)
sps->vcl_hrd_parameters_present_flag = get_bits1(&s->gb);
if(sps->vcl_hrd_parameters_present_flag)
decode_hrd_parameters(h, sps);
if(nal_hrd_parameters_present_flag || vcl_hrd_parameters_present_flag)
if(sps->nal_hrd_parameters_present_flag || sps->vcl_hrd_parameters_present_flag)
get_bits1(&s->gb); /* low_delay_hrd_flag */
get_bits1(&s->gb); /* pic_struct_present_flag */
sps->pic_struct_present_flag = get_bits1(&s->gb);
sps->bitstream_restriction_flag = get_bits1(&s->gb);
if(sps->bitstream_restriction_flag){
@ -7639,9 +7689,60 @@ static int decode_frame(AVCodecContext *avctx,
*data_size = 0;
} else {
cur->interlaced_frame = FIELD_OR_MBAFF_PICTURE;
/* Derive top_field_first from field pocs. */
cur->top_field_first = cur->field_poc[0] < cur->field_poc[1];
cur->repeat_pict = 0;
/* Signal interlacing information externally. */
/* Prioritize picture timing SEI information over used decoding process if it exists. */
if(h->sps.pic_struct_present_flag){
switch (h->sei_pic_struct)
{
case SEI_PIC_STRUCT_FRAME:
cur->interlaced_frame = 0;
break;
case SEI_PIC_STRUCT_TOP_FIELD:
case SEI_PIC_STRUCT_BOTTOM_FIELD:
case SEI_PIC_STRUCT_TOP_BOTTOM:
case SEI_PIC_STRUCT_BOTTOM_TOP:
cur->interlaced_frame = 1;
break;
case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
// Signal the possibility of telecined film externally (pic_struct 5,6)
// From these hints, let the applications decide if they apply deinterlacing.
cur->repeat_pict = 1;
cur->interlaced_frame = FIELD_OR_MBAFF_PICTURE;
break;
case SEI_PIC_STRUCT_FRAME_DOUBLING:
// Force progressive here, as doubling interlaced frame is a bad idea.
cur->interlaced_frame = 0;
cur->repeat_pict = 2;
break;
case SEI_PIC_STRUCT_FRAME_TRIPLING:
cur->interlaced_frame = 0;
cur->repeat_pict = 4;
break;
}
}else{
/* Derive interlacing flag from used decoding process. */
cur->interlaced_frame = FIELD_OR_MBAFF_PICTURE;
}
if (cur->field_poc[0] != cur->field_poc[1]){
/* Derive top_field_first from field pocs. */
cur->top_field_first = cur->field_poc[0] < cur->field_poc[1];
}else{
if(cur->interlaced_frame || h->sps.pic_struct_present_flag){
/* Use picture timing SEI information. Even if it is a information of a past frame, better than nothing. */
if(h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM
|| h->sei_pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM_TOP)
cur->top_field_first = 1;
else
cur->top_field_first = 0;
}else{
/* Most likely progressive */
cur->top_field_first = 0;
}
}
//FIXME do something with unavailable reference frames

26
libavcodec/h264.h
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@ -110,6 +110,21 @@ enum {
NAL_AUXILIARY_SLICE=19
};
/**
* pic_struct in picture timing SEI message
*/
typedef enum {
SEI_PIC_STRUCT_FRAME = 0, ///< 0: %frame
SEI_PIC_STRUCT_TOP_FIELD = 1, ///< 1: top field
SEI_PIC_STRUCT_BOTTOM_FIELD = 2, ///< 2: bottom field
SEI_PIC_STRUCT_TOP_BOTTOM = 3, ///< 3: top field, bottom field, in that order
SEI_PIC_STRUCT_BOTTOM_TOP = 4, ///< 4: bottom field, top field, in that order
SEI_PIC_STRUCT_TOP_BOTTOM_TOP = 5, ///< 5: top field, bottom field, top field repeated, in that order
SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM = 6, ///< 6: bottom field, top field, bottom field repeated, in that order
SEI_PIC_STRUCT_FRAME_DOUBLING = 7, ///< 7: %frame doubling
SEI_PIC_STRUCT_FRAME_TRIPLING = 8 ///< 8: %frame tripling
} SEI_PicStructType;
/**
* Sequence parameter set
*/
@ -150,6 +165,12 @@ typedef struct SPS{
int scaling_matrix_present;
uint8_t scaling_matrix4[6][16];
uint8_t scaling_matrix8[2][64];
int nal_hrd_parameters_present_flag;
int vcl_hrd_parameters_present_flag;
int pic_struct_present_flag;
int time_offset_length;
int cpb_removal_delay_length; ///< cpb_removal_delay_length_minus1 + 1
int dpb_output_delay_length; ///< dpb_output_delay_length_minus1 + 1
}SPS;
/**
@ -460,6 +481,11 @@ typedef struct H264Context{
int mb_xy;
uint32_t svq3_watermark_key;
/**
* pic_struct in picture timing SEI message
*/
SEI_PicStructType sei_pic_struct;
}H264Context;
#endif /* AVCODEC_H264_H */

4
libavcodec/h264data.h
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@ -1296,4 +1296,8 @@ static const int8_t cabac_context_init_PB[3][460][2] =
}
};
static const uint8_t sei_num_clock_ts_table[9]={
1, 1, 1, 2, 2, 3, 3, 2, 3
};
#endif /* AVCODEC_H264DATA_H */

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