Initial commit of all previous Chrome build scripts.

chromium/patches/to_upstream/12_ogg_seek_to_zero.patch

+diff -wurp -N orig/libavformat/oggdec.c ffmpeg/libavformat/oggdec.c
+--- orig/libavformat/oggdec.c   2011-07-12 20:48:31.175020888 -0700
++++ ffmpeg/libavformat/oggdec.c 2011-07-12 20:48:31.225013975 -0700
+@@ -618,6 +618,8 @@ static int64_t ogg_read_timestamp(AVForm
+     AVIOContext *bc = s->pb;
+     int64_t pts = AV_NOPTS_VALUE;
+     int i = -1;
++    int packet = 0;
++    int64_t start_pos = *pos_arg;
+     avio_seek(bc, *pos_arg, SEEK_SET);
+     ogg_reset(ogg);
+ 
+@@ -627,6 +629,12 @@ static int64_t ogg_read_timestamp(AVForm
+             pts = ogg_calc_pts(s, i, NULL);
+             if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
+                 pts = AV_NOPTS_VALUE;
++
++            // This is for the special case for the first packet in the stream.
++            if (pts == AV_NOPTS_VALUE && start_pos <= s->data_offset && !packet) {
++                pts = 0;
++            }
++            ++packet;
+         }
+         if (pts != AV_NOPTS_VALUE)
+             break;
+@@ -641,6 +649,10 @@ static int ogg_read_seek(AVFormatContext
+     struct ogg *ogg = s->priv_data;
+     struct ogg_stream *os = ogg->streams + stream_index;
+     int ret;
++    int64_t seek_pos;
++    int64_t pos_arg;
++    int64_t seek_pts;
++    int i;
+ 
+     // Try seeking to a keyframe first. If this fails (very possible),
+     // av_seek_frame will fall back to ignoring keyframes
+@@ -652,6 +664,22 @@ static int ogg_read_seek(AVFormatContext
+     os = ogg->streams + stream_index;
+     if (ret < 0)
+         os->keyframe_seek = 0;
++
++    // Save the position seeked to.
++    pos_arg = seek_pos = url_ftell(s->pb);
++    seek_pts = ogg_read_timestamp(s, stream_index, &pos_arg, url_fsize(s->pb));
++    os = ogg->streams + stream_index;
++
++    // Since we have seeked to the beginning then reset lastpts and lastdts to 0.
++    if (!seek_pts) {
++        for (i = 0; i < ogg->nstreams; i++){
++            struct ogg_stream *stream = ogg->streams + i;
++            stream->lastpts = 0;
++            stream->lastdts = 0;
++        }
++        os->keyframe_seek = 0;
++    }
++    url_fseek(s->pb, seek_pos, SEEK_SET);
+     return ret;
+ }
+