[vlc-commits] hevc_nal: parse slice_segment_header
Francois Cartegnie
git at videolan.org
Tue Dec 15 17:23:47 CET 2015
vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Mon Dec 14 14:58:57 2015 +0100| [48ceb00c1510c46e71177d2a26cec883cc7fb928] | committer: Francois Cartegnie
hevc_nal: parse slice_segment_header
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=48ceb00c1510c46e71177d2a26cec883cc7fb928
---
modules/packetizer/hevc_nal.c | 105 +++++++++++++++++++++++++++++++++++++++++
modules/packetizer/hevc_nal.h | 12 +++++
2 files changed, 117 insertions(+)
diff --git a/modules/packetizer/hevc_nal.c b/modules/packetizer/hevc_nal.c
index fa174cb..14db1a4 100644
--- a/modules/packetizer/hevc_nal.c
+++ b/modules/packetizer/hevc_nal.c
@@ -178,6 +178,19 @@ struct hevc_picture_parameter_set_t
};
+struct hevc_slice_segment_header_t
+{
+ nal_u1_t first_slice_segment_in_pic_flag;
+ nal_u1_t no_output_of_prior_pics_flag;
+ nal_ue_t slice_pic_parameter_set_id;
+ nal_u1_t dependent_slice_segment_flag;
+ // slice_segment_address; read but discarded
+ nal_ue_t slice_type;
+ nal_u1_t pic_output_flag;
+ /* incomplete */
+
+};
+
/* Computes size and does check the whole struct integrity */
static size_t get_hvcC_to_AnnexB_NAL_size( const uint8_t *p_buf, size_t i_buf )
{
@@ -595,3 +608,95 @@ hevc_picture_parameter_set_t * hevc_rbsp_decode_pps( const uint8_t *p_buf, size_
}
return p_pps;
}
+
+static bool hevc_get_picture_CtbsYsize( const hevc_sequence_parameter_set_t *p_sps, unsigned *p_w, unsigned *p_h )
+{
+ const unsigned int MinCbLog2SizeY = p_sps->log2_min_luma_coding_block_size_minus3 + 3;
+ const unsigned int CtbLog2SizeY = MinCbLog2SizeY + p_sps->log2_diff_max_min_luma_coding_block_size;
+ if( CtbLog2SizeY > 32 )
+ return false;
+ const unsigned int CtbSizeY = 1 << CtbLog2SizeY;
+ *p_w = (p_sps->pic_width_in_luma_samples - 1) / CtbSizeY + 1;
+ *p_h = (p_sps->pic_height_in_luma_samples - 1) / CtbSizeY + 1;
+ return true;
+}
+
+static bool hevc_parse_slice_segment_header_rbsp( bs_t *p_bs,
+ const hevc_sequence_parameter_set_t **pp_sps,
+ const hevc_picture_parameter_set_t **pp_pps,
+ hevc_slice_segment_header_t *p_sl )
+{
+ if( bs_remain( p_bs ) < 3 )
+ return false;
+
+ p_sl->first_slice_segment_in_pic_flag = bs_read1( p_bs );
+ p_sl->no_output_of_prior_pics_flag = bs_read1( p_bs );
+ p_sl->slice_pic_parameter_set_id = bs_read_ue( p_bs );
+ if( p_sl->slice_pic_parameter_set_id >= HEVC_PPS_MAX || bs_remain( p_bs ) < 1 )
+ return false;
+
+ const hevc_picture_parameter_set_t *p_pps = pp_pps[p_sl->slice_pic_parameter_set_id];
+ if(!p_pps)
+ return false;
+
+ if( !p_sl->first_slice_segment_in_pic_flag )
+ {
+ if( p_pps->dependent_slice_segments_enabled_flag )
+ p_sl->dependent_slice_segment_flag = bs_read1( p_bs );
+
+ const hevc_sequence_parameter_set_t *p_sps = pp_sps[p_pps->pps_seq_parameter_set_id];
+ if( p_sps )
+ return false;
+
+ unsigned w, h;
+ if( !hevc_get_picture_CtbsYsize( p_sps, &w, &h ) )
+ return false;
+
+ (void) bs_read( p_bs, vlc_ceil_log2( w * h ) ); /* slice_segment_address */
+ }
+
+ if( !p_sl->dependent_slice_segment_flag )
+ {
+ if( p_pps->num_extra_slice_header_bits )
+ (void) bs_read( p_bs, p_pps->num_extra_slice_header_bits );
+
+ p_sl->slice_type = bs_read_ue( p_bs );
+ if( p_sl->slice_type > HEVC_SLICE_TYPE_I )
+ return false;
+
+ if( p_pps->output_flag_present_flag )
+ p_sl->pic_output_flag = bs_read1( p_bs );
+ }
+
+ if( bs_remain( p_bs ) < 1 )
+ return false;
+
+ return true;
+}
+
+void hevc_rbsp_release_slice_header( hevc_slice_segment_header_t *p_sh )
+{
+ free( p_sh );
+}
+
+hevc_slice_segment_header_t * hevc_rbsp_decode_slice_header( const uint8_t *p_buf, size_t i_buf,
+ const hevc_sequence_parameter_set_t **pp_sps,
+ const hevc_picture_parameter_set_t **pp_pps )
+{
+ if(!pp_sps || !pp_pps)
+ return NULL;
+
+ hevc_slice_segment_header_t *p_sh = calloc(1, sizeof(hevc_slice_segment_header_t));
+ if(likely(p_sh))
+ {
+ bs_t bs;
+ bs_init( &bs, p_buf, i_buf );
+ bs_skip( &bs, 16 ); /* Skip nal_unit_header */
+ if( !hevc_parse_slice_segment_header_rbsp( &bs, pp_sps, pp_pps, p_sh ) )
+ {
+ hevc_rbsp_release_slice_header( p_sh );
+ p_sh = NULL;
+ }
+ }
+ return p_sh;
+}
diff --git a/modules/packetizer/hevc_nal.h b/modules/packetizer/hevc_nal.h
index aa30aee..cc7aa4f 100644
--- a/modules/packetizer/hevc_nal.h
+++ b/modules/packetizer/hevc_nal.h
@@ -112,6 +112,13 @@ enum hevc_nal_unit_type_e
HEVC_NAL_UNKNOWN
};
+enum hevc_slice_type_e
+{
+ HEVC_SLICE_TYPE_B = 0,
+ HEVC_SLICE_TYPE_P,
+ HEVC_SLICE_TYPE_I
+};
+
#define HEVC_MIN_HVCC_SIZE 23
/* checks if data is an HEVCDecoderConfigurationRecord */
@@ -131,12 +138,17 @@ static inline bool hevc_ishvcC( const uint8_t *p_buf, size_t i_buf )
/* NAL decoding */
typedef struct hevc_sequence_parameter_set_t hevc_sequence_parameter_set_t;
typedef struct hevc_picture_parameter_set_t hevc_picture_parameter_set_t;
+typedef struct hevc_slice_segment_header_t hevc_slice_segment_header_t;
hevc_sequence_parameter_set_t * hevc_rbsp_decode_sps( const uint8_t *, size_t ) VLC_USED;
hevc_picture_parameter_set_t * hevc_rbsp_decode_pps( const uint8_t *, size_t ) VLC_USED;
+hevc_slice_segment_header_t * hevc_rbsp_decode_slice_header( const uint8_t *, size_t,
+ const hevc_sequence_parameter_set_t **pp_sps/* HEVC_MAX_SPS */,
+ const hevc_picture_parameter_set_t **pp_pps /* HEVC_MAX_PPS */) VLC_USED;
void hevc_rbsp_release_sps( hevc_sequence_parameter_set_t * );
void hevc_rbsp_release_pps( hevc_picture_parameter_set_t * );
+void hevc_rbsp_release_slice_header( hevc_slice_segment_header_t * );
/* Converts HEVCDecoderConfigurationRecord to Annex B format */
uint8_t * hevc_hvcC_to_AnnexB_NAL( const uint8_t *p_buf, size_t i_buf,
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