[Iaxclient-cvs] SF.net SVN: iaxclient:[1462] trunk/lib/codec_theora.c

[<bc...@us...>]

Revision: 1462
          http://iaxclient.svn.sourceforge.net/iaxclient/?rev=1462&view=rev
Author:   bcholew
Date:     2010-01-29 15:50:24 +0000 (Fri, 29 Jan 2010)

Log Message:
-----------
Iaxclient now refrains from decoding a theora frame from a new video source
(sender) until a keyframe arrives. This avoids visual artifacts from applying
new-source p-frame changes to the final image from the previous source.

Modified Paths:
--------------
    trunk/lib/codec_theora.c

Modified: trunk/lib/codec_theora.c
===================================================================
--- trunk/lib/codec_theora.c	2010-01-29 15:29:04 UTC (rev 1461)
+++ trunk/lib/codec_theora.c	2010-01-29 15:50:24 UTC (rev 1462)
@@ -66,6 +66,7 @@
 	theora_comment          tc;
 	struct deslicer_context *dsc;
 	int                     got_key_frame;
+	unsigned short          prev_src_id;
 };
 
 struct theora_encoder
@@ -143,8 +144,12 @@
 	op.bytes = flen;
 	op.packet = (unsigned char *)frame;
 
-	/* reject all incoming frames until we get a key frame */
-	if ( !d->got_key_frame )
+	/* Reject all incoming frames until we get a key frame.
+	 * Similarly, check for a change in who is sending the video.
+	 * We shouldn't use frames from a new source until
+	 * we get a keyframe
+	 */
+	if ( !d->got_key_frame || d->prev_src_id != d->dsc->source_id )
 	{
 		if ( theora_packet_iskeyframe(&op) )
 			d->got_key_frame = 1;
@@ -179,6 +184,10 @@
 		return -1;
 	}
 
+	// keep track of the source id (from the most
+	// recent valid desliced frame) to detect a switch
+	d->prev_src_id = d->dsc->source_id;
+
 	//clear output
 	memset(out, 127, my_out_len);
 


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