/*****************************************************************************
* DecodePacket: decodes a Theora packet.
*****************************************************************************/
static picture_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
{
decoder_sys_t *p_sys = p_dec->p_sys;
picture_t *p_pic;
yuv_buffer yuv;
theora_decode_packetin( &p_sys->td, p_oggpacket );
/* Check for keyframe */
if( !(p_oggpacket->packet[0] & 0x80) /* data packet */ &&
!(p_oggpacket->packet[0] & 0x40) /* intra frame */ )
p_sys->b_decoded_first_keyframe = true;
/* If we haven't seen a single keyframe yet, don't let Theora decode
* anything, otherwise we'll get display artifacts. (This is impossible
* in the general case, but can happen if e.g. we play a network stream
* using a timed URL, such that the server doesn't start the video with a
* keyframe). */
if( p_sys->b_decoded_first_keyframe )
theora_decode_YUVout( &p_sys->td, &yuv );
else
return NULL;
/* Get a new picture */
p_pic = decoder_NewPicture( p_dec );
if( !p_pic ) return NULL;
theora_CopyPicture( p_pic, &yuv );
p_pic->date = p_sys->i_pts;
return p_pic;
}
/*****************************************************************************
* DecodePacket: decodes a Theora packet.
*****************************************************************************/
static picture_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
{
decoder_sys_t *p_sys = p_dec->p_sys;
picture_t *p_pic;
th_ycbcr_buffer ycbcr;
/* TODO: Implement _granpos (3rd parameter here) and add the
* call to TH_DECCTL_SET_GRANDPOS after seek */
/* TODO: If the return is TH_DUPFRAME, we don't need to display a new
* frame, but we do need to keep displaying the previous one. */
if (th_decode_packetin( p_sys->tcx, p_oggpacket, NULL ) < 0)
return NULL; /* bad packet */
/* Check for keyframe */
if( !(p_oggpacket->packet[0] & 0x80) /* data packet */ &&
!(p_oggpacket->packet[0] & 0x40) /* intra frame */ )
p_sys->b_decoded_first_keyframe = true;
/* If we haven't seen a single keyframe yet, don't let Theora decode
* anything, otherwise we'll get display artifacts. (This is impossible
* in the general case, but can happen if e.g. we play a network stream
* using a timed URL, such that the server doesn't start the video with a
* keyframe). */
if( !p_sys->b_decoded_first_keyframe )
return NULL; /* Wait until we've decoded the first keyframe */
if( th_decode_ycbcr_out( p_sys->tcx, ycbcr ) ) /* returns 0 on success */
return NULL;
/* Get a new picture */
if( decoder_UpdateVideoFormat( p_dec ) )
return NULL;
p_pic = decoder_NewPicture( p_dec );
if( !p_pic ) return NULL;
theora_CopyPicture( p_pic, ycbcr );
p_pic->date = p_sys->i_pts;
p_pic->b_progressive = true;
return p_pic;
}
