[FFmpeg-devel] [PATCH] VC-1 SP/MP test bitstreams demuxer

Kostya kostya.shishkov
Sat Jan 26 18:48:08 CET 2008


On Sat, Jan 26, 2008 at 05:49:04PM +0100, Michael Niedermayer wrote:
> On Sat, Jan 26, 2008 at 05:46:01PM +0200, Kostya wrote:
> > $subj, taken from 2006 SoC project and updated for current API.
> 
[review skipped]

Here is simplified version, now without context and redundant copies.
Other stuff is simplified a bit too.
 
> [...]
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
-------------- next part --------------
Index: libavformat/vc1test.c
===================================================================
--- libavformat/vc1test.c	(revision 0)
+++ libavformat/vc1test.c	(revision 0)
@@ -0,0 +1,95 @@
+/*
+ * VC1 Test Bitstreams Format Demuxer
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file vc1test.c
+ * VC1 test bitstreams file demuxer
+ * by Konstantin Shishkov
+ * Format specified in SMPTE standard 421 Annex L
+ */
+
+#include "avformat.h"
+
+#define VC1_EXTRADATA_SIZE 4
+
+static int vc1t_probe(AVProbeData *p)
+{
+    if (p->buf[3] != 0xC5 && AV_RL32(&p->buf[4]) != 4)
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int vc1t_read_header(AVFormatContext *s,
+                           AVFormatParameters *ap)
+{
+    ByteIOContext *pb = s->pb;
+    AVStream *st;
+
+    url_fskip(pb, 3); //frame count, little-endian
+    if(get_byte(pb) != 0xC5 || get_le32(pb) != 4)
+        return -1;
+
+    /* init video codec */
+    st = av_new_stream(s, 0);
+    if (!st)
+        return -1;
+
+    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_id = CODEC_ID_WMV3;
+
+    st->codec->extradata = av_malloc(VC1_EXTRADATA_SIZE);
+    st->codec->extradata_size = VC1_EXTRADATA_SIZE;
+    get_buffer(pb, st->codec->extradata, VC1_EXTRADATA_SIZE);
+    st->codec->height = get_le32(pb);
+    st->codec->width = get_le32(pb);
+    if(get_le32(pb) != 0xC)
+        return -1;
+    url_fskip(pb, 8);
+    av_set_pts_info(st, 33, 1, get_le32(pb));
+
+    return 0;
+}
+
+static int vc1t_read_packet(AVFormatContext *s,
+                           AVPacket *pkt)
+{
+    ByteIOContext *pb = s->pb;
+    int frame_size;
+    int keyframe = 0;
+
+    frame_size = get_le24(pb);
+    if(get_byte(pb) & 0x80)
+        keyframe = 1;
+    url_fskip(pb, 4); // timestamp in ms
+    if(av_get_packet(pb, pkt, frame_size) < 0)
+        return AVERROR(EIO);
+    pkt->flags |= keyframe ? PKT_FLAG_KEY : 0;
+
+    return pkt->size;
+}
+
+AVInputFormat vc1t_demuxer = {
+    "vc1test",
+    "VC1 test bitstream format",
+    0,
+    vc1t_probe,
+    vc1t_read_header,
+    vc1t_read_packet,
+};
Index: libavformat/Makefile
===================================================================
--- libavformat/Makefile	(revision 11619)
+++ libavformat/Makefile	(working copy)
@@ -162,6 +162,7 @@
 OBJS-$(CONFIG_TTA_DEMUXER)               += tta.o
 OBJS-$(CONFIG_TXD_DEMUXER)               += txd.o
 OBJS-$(CONFIG_VC1_DEMUXER)               += raw.o
+OBJS-$(CONFIG_VC1T_DEMUXER)              += vc1test.o
 OBJS-$(CONFIG_VMD_DEMUXER)               += sierravmd.o
 OBJS-$(CONFIG_VOC_DEMUXER)               += vocdec.o voc.o
 OBJS-$(CONFIG_VOC_MUXER)                 += vocenc.o voc.o
Index: libavformat/allformats.c
===================================================================
--- libavformat/allformats.c	(revision 11619)
+++ libavformat/allformats.c	(working copy)
@@ -156,6 +156,7 @@
     REGISTER_DEMUXER  (TTA, tta);
     REGISTER_DEMUXER  (TXD, txd);
     REGISTER_DEMUXER  (VC1, vc1);
+    REGISTER_DEMUXER  (VC1T, vc1t);
     REGISTER_DEMUXER  (VMD, vmd);
     REGISTER_MUXDEMUX (VOC, voc);
     REGISTER_MUXDEMUX (WAV, wav);



More information about the ffmpeg-devel mailing list