Skip video data until one keyframe is detected.

This is done for VP3 and VP6 bitstreams, the detection logic is based on mplayer's nsv demuxer.
Streams beginning with "Z092" are not yet supported.

CVS patchset: 7135
CVS date: 2004/11/19 00:30:17

1 files changed, 44 insertions, 12 deletions

diff --git a/src/demuxers/demux_nsv.c b/src/demuxers/demux_nsv.c
index a29cd9ca8..262584c76 100644
--- a/src/demuxers/demux_nsv.c
+++ b/src/demuxers/demux_nsv.c
@@ -23,7 +23,7 @@
  * For more information regarding the NSV file format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  *
- * $Id: demux_nsv.c,v 1.17 2004/06/13 21:28:54 miguelfreitas Exp $
+ * $Id: demux_nsv.c,v 1.18 2004/11/19 00:30:17 tmattern Exp $
  */
 
 #ifdef HAVE_CONFIG_H
@@ -74,6 +74,8 @@ typedef struct {
   int64_t              video_pts;
   unsigned int         audio_type;
 
+  int                  keyframe_found;
+
   xine_bmiheader       bih;
 } demux_nsv_t;
 
@@ -98,7 +100,7 @@ static int open_nsv_file(demux_nsv_t *this) {
       (preview[2] != 'V'))
   {
     if ((preview[0] != 'Z') ||
-        (preview[1] != 0) ||
+        (preview[1] != 0)   ||
 	(preview[2] != '9') ||
 	(preview[3] != 1))
           return 0;
@@ -294,6 +296,8 @@ static int demux_nsv_send_chunk(demux_plugin_t *this_gen) {
     video_size, audio_size);
 
   while (video_size) {
+    int buf_num = 0;
+
     buf = this->video_fifo->buffer_pool_alloc (this->video_fifo);
 
     if (video_size > buf->max_size)
@@ -308,17 +312,45 @@ static int demux_nsv_send_chunk(demux_plugin_t *this_gen) {
       return this->status;
     }
 
-    buf->type = this->video_type;
-    if( this->data_size )
-      buf->extra_info->input_normpos = (int)((double)current_file_pos * 65535 / this->data_size);
-    buf->extra_info->input_time = this->video_pts / 90;
-    buf->pts = this->video_pts;
-    buf->decoder_flags |= BUF_FLAG_FRAMERATE;
-    buf->decoder_info[0] = this->frame_pts_inc;
+    /* HACK: parse decoder data to detect a keyframe */
+    if ((buf_num == 0) && (!this->keyframe_found)) {
+      switch (this->video_type) {
+      case BUF_VIDEO_VP31:
+	if ((buf->content[1] == 0x00) && (buf->content[2] == 0x08)) {
+	  lprintf("keyframe detected !\n");
+	  this->keyframe_found = 1;
+	}
+	break;
+
+      case BUF_VIDEO_VP6:
+	if ((buf->content[1] & 0x0e) == 0x06) {
+	  lprintf("keyframe detected !\n");
+	  this->keyframe_found = 1;
+	}
+	break;
 
-    if (!video_size)
-      buf->decoder_flags |= BUF_FLAG_FRAME_END;
-    this->video_fifo->put(this->video_fifo, buf);
+      default:
+	/* don't know how to detect keyframe */
+	this->keyframe_found = 1;
+      }
+      buf_num++;
+    }
+
+    if (this->keyframe_found) {
+      buf->type = this->video_type;
+      if( this->data_size )
+	buf->extra_info->input_normpos = (int)((double)current_file_pos * 65535 / this->data_size);
+      buf->extra_info->input_time = this->video_pts / 90;
+      buf->pts = this->video_pts;
+      buf->decoder_flags |= BUF_FLAG_FRAMERATE;
+      buf->decoder_info[0] = this->frame_pts_inc;
+
+      if (!video_size)
+	buf->decoder_flags |= BUF_FLAG_FRAME_END;
+      this->video_fifo->put(this->video_fifo, buf);
+    } else {
+      buf->free_buffer(buf);
+    }
   }
 
   while (audio_size) {