Adobe Filmstrip muxer and demuxer

Originally committed as revision 21212 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 111 insertions, 0 deletions

diff --git a/libavformat/filmstripdec.c b/libavformat/filmstripdec.c
new file mode 100644
index 0000000000..80c4157d8e
--- /dev/null
+++ b/libavformat/filmstripdec.c
@@ -0,0 +1,111 @@
+/*
+ * Adobe Filmstrip demuxer
+ * Copyright (c) 2010 Peter Ross
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file libavformat/filmstripdec.c
+ * Adobe Filmstrip demuxer
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+
+#define RAND_TAG MKBETAG('R','a','n','d')
+
+typedef struct {
+    int leading;
+} FilmstripDemuxContext;
+
+static int read_header(AVFormatContext *s,
+                       AVFormatParameters *ap)
+{
+    FilmstripDemuxContext *film = s->priv_data;
+    ByteIOContext *pb = s->pb;
+    AVStream *st;
+
+    if (url_is_streamed(s->pb))
+        return AVERROR(EIO);
+
+    url_fseek(pb, url_fsize(pb) - 36, SEEK_SET);
+    if (get_be32(pb) != RAND_TAG) {
+        av_log(s, AV_LOG_ERROR, "magic number not found");
+        return AVERROR_INVALIDDATA;
+    }
+
+    st = av_new_stream(s, 0);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->nb_frames = get_be32(pb);
+    if (get_be16(pb) != 0) {
+        av_log_ask_for_sample(s, "unsupported packing method\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    url_fskip(pb, 2);
+    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_id   = CODEC_ID_RAWVIDEO;
+    st->codec->pix_fmt    = PIX_FMT_RGBA;
+    st->codec->codec_tag  = 0; /* no fourcc */
+    st->codec->width      = get_be16(pb);
+    st->codec->height     = get_be16(pb);
+    film->leading         = get_be16(pb);
+    av_set_pts_info(st, 64, 1, get_be16(pb));
+
+    url_fseek(pb, 0, SEEK_SET);
+
+    return 0;
+}
+
+static int read_packet(AVFormatContext *s,
+                       AVPacket *pkt)
+{
+    FilmstripDemuxContext *film = s->priv_data;
+    AVStream *st = s->streams[0];
+
+    if (url_feof(s->pb))
+        return AVERROR(EIO);
+    pkt->dts = url_ftell(s->pb) / (st->codec->width * (st->codec->height + film->leading) * 4);
+    pkt->size = av_get_packet(s->pb, pkt, st->codec->width * st->codec->height * 4);
+    url_fskip(s->pb, st->codec->width * film->leading * 4);
+    if (pkt->size < 0)
+        return pkt->size;
+    pkt->flags |= PKT_FLAG_KEY;
+    return 0;
+}
+
+static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+    AVStream *st = s->streams[stream_index];
+    url_fseek(s->pb, FFMAX(timestamp, 0) * st->codec->width * st->codec->height * 4, SEEK_SET);
+    return 0;
+}
+
+AVInputFormat filmstrip_demuxer = {
+    "filmstrip",
+    NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
+    sizeof(FilmstripDemuxContext),
+    NULL,
+    read_header,
+    read_packet,
+    NULL,
+    read_seek,
+    .extensions = "flm",
+};