Commit f815b9e5 authored by Thomas Guillem's avatar Thomas Guillem

h264_nal: add h264_get_spspps

It fetches the SPS and PPS pointers from an Annex B buffer.
parent bafd5804
......@@ -22,6 +22,8 @@
#include <limits.h>
static const uint8_t annexb_startcode[] = { 0x00, 0x00, 0x00, 0x01 };
int convert_sps_pps( decoder_t *p_dec, const uint8_t *p_buf,
uint32_t i_buf_size, uint8_t *p_out_buf,
uint32_t i_out_buf_size, uint32_t *p_sps_pps_size,
......@@ -138,6 +140,72 @@ void convert_h264_to_annexb( uint8_t *p_buf, uint32_t i_len,
}
}
int h264_get_spspps( uint8_t *p_buf, size_t i_buf,
uint8_t **pp_sps, size_t *p_sps_size,
uint8_t **pp_pps, size_t *p_pps_size )
{
uint8_t *p_sps = NULL, *p_pps = NULL;
size_t i_sps_size = 0, i_pps_size = 0;
int i_nal_type = NAL_UNKNOWN;
while( true )
{
int i_inc = 0;
if( i_buf > 5 && memcmp( p_buf, annexb_startcode, 4 ) == 0 )
{
i_nal_type = p_buf[4] & 0x1F;
/* size of startcode + nal_type */
i_inc = 5;
/* pointer to the beginning of the sps/pps */
if( i_nal_type == NAL_SPS && !p_sps )
p_sps = p_buf;
if( i_nal_type == NAL_PPS && !p_pps )
p_pps = p_buf;
} else {
i_inc = 1;
}
/* cf. 7.4.1.2.3 */
if( i_nal_type == NAL_UNKNOWN || i_nal_type > 18
|| (i_nal_type >= 10 && i_nal_type <= 12))
return -1;
/* update SPS/PPS size if the new NAL is different than the last one */
if( !i_sps_size && p_sps && i_nal_type != NAL_SPS )
i_sps_size = p_buf - p_sps;
if( !i_pps_size && p_pps && i_nal_type != NAL_PPS )
i_pps_size = p_buf - p_pps;
/* SPS/PPS are before the slices */
if (i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
break;
i_buf -= i_inc;
p_buf += i_inc;
if( i_buf == 0 )
{
/* update SPS/PPS size if we reach the end of the buffer */
if( !i_sps_size && p_sps )
i_sps_size = p_buf - p_sps;
if( !i_pps_size && p_pps )
i_pps_size = p_buf - p_pps;
break;
}
}
if( ( !p_sps || !i_sps_size ) && ( !p_pps || !i_pps_size ) )
return -1;
*pp_sps = p_sps;
*p_sps_size = i_sps_size;
*pp_pps = p_pps;
*p_pps_size = i_pps_size;
return 0;
}
bool h264_get_profile_level(const es_format_t *p_fmt, size_t *p_profile,
size_t *p_level, size_t *p_nal_size)
{
......
......@@ -82,6 +82,12 @@ void convert_h264_to_annexb( uint8_t *p_buf, uint32_t i_len,
size_t i_nal_size,
struct H264ConvertState *state );
/* Get the SPS/PPS pointers from an Annex B buffer
* Returns 0 if a SPS and/or a PPS is found */
int h264_get_spspps( uint8_t *p_buf, size_t i_buf,
uint8_t **pp_sps, size_t *p_sps_size,
uint8_t **pp_pps, size_t *p_pps_size );
/* Get level and Profile */
bool h264_get_profile_level(const es_format_t *p_fmt, size_t *p_profile,
size_t *p_level, size_t *p_nal_size);
......
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