@ -1,6 +1,7 @@
/*
* RTP VP8 Depacketizer
* Copyright ( c ) 2010 Josh Allmann
* Copyright ( c ) 2012 Martin Storsjo
*
* This file is part of FFmpeg .
*
@ -23,7 +24,7 @@
* @ file
* @ brief RTP support for the VP8 payload
* @ author Josh Allmann < joshua . allmann @ gmail . com >
* @ see http : //www.webmproject.org/code/specs/rtp/
* @ see http : //tools.ietf.org/html/draft-ietf-payload-vp8-05
*/
# include "libavcodec/bytestream.h"
@ -33,14 +34,12 @@
struct PayloadContext {
AVIOContext * data ;
uint32_t timestamp ;
int is_keyframe ;
} ;
static void prepare_packet ( AVPacket * pkt , PayloadContext * vp8 , int stream )
{
av_init_packet ( pkt ) ;
pkt - > stream_index = stream ;
pkt - > flags = vp8 - > is_keyframe ? AV_PKT_FLAG_KEY : 0 ;
pkt - > size = avio_close_dyn_buf ( vp8 - > data , & pkt - > data ) ;
pkt - > destruct = av_destruct_packet ;
vp8 - > data = NULL ;
@ -54,70 +53,84 @@ static int vp8_handle_packet(AVFormatContext *ctx,
const uint8_t * buf ,
int len , int flags )
{
int start_packet , end_packet , has_au , ret = AVERROR ( EAGAIN ) ;
if ( ! buf ) {
// only called when vp8_handle_packet returns 1
if ( ! vp8 - > data ) {
av_log ( ctx , AV_LOG_ERROR , " Invalid VP8 data passed \n " ) ;
int start_partition , end_packet ;
int extended_bits , non_ref , part_id ;
int pictureid_present = 0 , tl0picidx_present = 0 , tid_present = 0 ,
keyidx_present = 0 ;
int pictureid = - 1 , keyidx = - 1 ;
if ( len < 1 )
return AVERROR_INVALIDDATA ;
extended_bits = buf [ 0 ] & 0x80 ;
non_ref = buf [ 0 ] & 0x20 ;
start_partition = buf [ 0 ] & 0x10 ;
part_id = buf [ 0 ] & 0x0f ;
end_packet = flags & RTP_FLAG_MARKER ;
buf + + ;
len - - ;
if ( extended_bits ) {
if ( len < 1 )
return AVERROR_INVALIDDATA ;
pictureid_present = buf [ 0 ] & 0x80 ;
tl0picidx_present = buf [ 0 ] & 0x40 ;
tid_present = buf [ 0 ] & 0x20 ;
keyidx_present = buf [ 0 ] & 0x10 ;
buf + + ;
len - - ;
}
if ( pictureid_present ) {
if ( len < 1 )
return AVERROR_INVALIDDATA ;
if ( buf [ 0 ] & 0x80 ) {
if ( len < 2 )
return AVERROR_INVALIDDATA ;
pictureid = AV_RB16 ( buf ) & 0x7fff ;
buf + = 2 ;
len - = 2 ;
} else {
pictureid = buf [ 0 ] & 0x7f ;
buf + + ;
len - - ;
}
prepare_packet ( pkt , vp8 , st - > index ) ;
* timestamp = vp8 - > timestamp ;
return 0 ;
}
if ( tl0picidx_present ) {
// Ignoring temporal level zero index
buf + + ;
len - - ;
}
if ( tid_present | | keyidx_present ) {
// Ignoring temporal layer index and layer sync bit
if ( len < 1 )
return AVERROR_INVALIDDATA ;
if ( keyidx_present )
keyidx = buf [ 0 ] & 0x1f ;
buf + + ;
len - - ;
}
if ( len < 1 )
return AVERROR_INVALIDDATA ;
start_packet = * buf & 1 ;
end_packet = flags & RTP_FLAG_MARKER ;
has_au = * buf & 2 ;
buf + + ;
len - - ;
if ( start_packet ) {
if ( start_partition & & part_id = = 0 ) {
int res ;
uint32_t ts = * timestamp ;
if ( vp8 - > data ) {
// missing end marker; return old frame anyway. untested
prepare_packet ( pkt , vp8 , st - > index ) ;
* timestamp = vp8 - > timestamp ; // reset timestamp from old frame
// if current frame fits into one rtp packet, need to hold
// that for the next av_get_packet call
ret = end_packet ? 1 : 0 ;
uint8_t * tmp ;
avio_close_dyn_buf ( vp8 - > data , & tmp ) ;
av_free ( tmp ) ;
vp8 - > data = NULL ;
}
if ( ( res = avio_open_dyn_buf ( & vp8 - > data ) ) < 0 )
return res ;
vp8 - > is_keyframe = * buf & 1 ;
vp8 - > timestamp = ts ;
vp8 - > timestamp = * timestamp ;
}
if ( ! vp8 - > data | | vp8 - > timestamp ! = * timestamp & & ret = = AVERROR ( EAGAIN ) ) {
if ( ! vp8 - > data | | vp8 - > timestamp ! = * timestamp ) {
av_log ( ctx , AV_LOG_WARNING ,
" Received no start marker; dropping frame \n " ) ;
return AVERROR ( EAGAIN ) ;
}
// cycle through VP8AU headers if needed
// not tested with actual VP8AUs
while ( len ) {
int au_len = len ;
if ( has_au & & len > 2 ) {
au_len = AV_RB16 ( buf ) ;
buf + = 2 ;
len - = 2 ;
if ( buf + au_len > buf + len ) {
av_log ( ctx , AV_LOG_ERROR , " Invalid VP8AU length \n " ) ;
return AVERROR_INVALIDDATA ;
}
}
avio_write ( vp8 - > data , buf , au_len ) ;
buf + = au_len ;
len - = au_len ;
}
if ( ret ! = AVERROR ( EAGAIN ) ) // did we miss a end marker?
return ret ;
avio_write ( vp8 - > data , buf , len ) ;
if ( end_packet ) {
prepare_packet ( pkt , vp8 , st - > index ) ;
@ -129,8 +142,6 @@ static int vp8_handle_packet(AVFormatContext *ctx,
static PayloadContext * vp8_new_context ( void )
{
av_log ( NULL , AV_LOG_ERROR , " RTP VP8 payload implementation is incompatible "
" with the latest spec drafts. \n " ) ;
return av_mallocz ( sizeof ( PayloadContext ) ) ;
}
Michael Niedermayer
13 years ago