new mtv demuxer

Originally committed as revision 6667 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 186 insertions, 0 deletions

diff --git a/libavformat/mtv.c b/libavformat/mtv.c
new file mode 100644
index 0000000000..fff72b4739
--- /dev/null
+++ b/libavformat/mtv.c
@@ -0,0 +1,186 @@
+/*
+ * mtv demuxer
+ * Copyright (c) 2006 Reynaldo H. Verdejo Pinochet
+ *
+ * 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 mtv.c
+ * MTV demuxer.
+ */
+
+#include "avformat.h"
+#include "bswap.h"
+
+#define MTV_ASUBCHUNK_DATA_SIZE 500
+#define MTV_HEADER_SIZE 512
+#define MTV_AUDIO_PADDING_SIZE 12
+#define AUDIO_SAMPLING_RATE 44100
+#define VIDEO_SID 0
+#define AUDIO_SID 1
+
+typedef struct MTVDemuxContext {
+
+    unsigned int        file_size;         ///< filesize, not always right
+    unsigned int        segments;          ///< number of 512 byte segments
+    unsigned int        audio_identifier;  ///< 'MP3' on all files I have seen
+    unsigned int        audio_br;          ///< bitrate of audio chanel (mp3)
+    unsigned int        img_colorfmt;      ///< frame colorfmt rgb 565/555
+    unsigned int        img_bpp;           ///< frame bits per pixel
+    unsigned int        img_width;         //
+    unsigned int        img_height;        //
+    unsigned int        img_segment_size;  ///< size of image segment
+    unsigned int        video_fps;         //
+    unsigned int        audio_subsegments; ///< audio subsegments on one segment
+
+    uint8_t             audio_packet_count;
+
+} MTVDemuxContext;
+
+static int mtv_probe(AVProbeData *p)
+{
+    if(p->buf_size < 3)
+        return 0;
+
+    /* Magic is 'AMV' */
+
+    if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    MTVDemuxContext    *mtv = s->priv_data;
+    ByteIOContext      *pb  = &s->pb;
+    AVStream           *st;
+
+
+    url_fskip(pb, 3);
+    mtv->file_size         = get_le32(pb);
+    mtv->segments          = get_le32(pb);
+    url_fskip(pb, 32);
+    mtv->audio_identifier  = get_le24(pb);
+    mtv->audio_br          = get_le16(pb);
+    mtv->img_colorfmt      = get_le24(pb);
+    mtv->img_bpp           = get_byte(pb);
+    mtv->img_width         = get_le16(pb);
+    mtv->img_height        = get_le16(pb);
+    mtv->img_segment_size  = get_le16(pb);
+    url_fskip(pb, 4);
+    mtv->audio_subsegments = get_le16(pb);
+    mtv->video_fps         = (mtv->audio_br / 4) / mtv->audio_subsegments;
+
+    /* FIXME Add sanity check here */
+
+    /* first packet is allways audio*/
+
+    mtv->audio_packet_count = 1;
+
+    /* all systems go! init decoders */
+
+    /* video - raw rgb565 */
+
+    st = av_new_stream(s, VIDEO_SID);
+    if(!st)
+        return AVERROR_NOMEM;
+
+    av_set_pts_info(st, 64, 1, mtv->video_fps);
+    st->codec->codec_type      = CODEC_TYPE_VIDEO;
+    st->codec->codec_id        = CODEC_ID_RAWVIDEO;
+    st->codec->width           = mtv->img_width;
+    st->codec->height          = mtv->img_height;
+    st->codec->bits_per_sample = mtv->img_bpp;
+    st->codec->sample_rate     = mtv->video_fps;
+
+    /* audio - mp3 */
+
+    st = av_new_stream(s, AUDIO_SID);
+    if(!st)
+        return AVERROR_NOMEM;
+
+    av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE);
+    st->codec->codec_type      = CODEC_TYPE_AUDIO;
+    st->codec->codec_id        = CODEC_ID_MP3;
+    st->codec->bit_rate        = mtv->audio_br;
+    st->need_parsing=1;
+
+    /* Jump over header */
+
+    if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
+        return AVERROR_IO;
+
+    return(0);
+
+}
+
+static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    MTVDemuxContext *mtv = s->priv_data;
+    ByteIOContext *pb = &s->pb;
+    int ret;
+#ifndef WORDS_BIGENDIAN
+    int i;
+#endif
+
+    ret = 0;
+
+    if(mtv->audio_subsegments >= mtv->audio_packet_count)
+    {
+        url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
+
+        ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
+        if(ret != MTV_ASUBCHUNK_DATA_SIZE)
+            return AVERROR_IO;
+
+        mtv->audio_packet_count++;
+        pkt->stream_index = AUDIO_SID;
+
+    }else
+    {
+        ret = av_get_packet(pb, pkt, mtv->img_segment_size);
+        if(ret != mtv->img_segment_size)
+            return AVERROR_IO;
+
+#ifndef WORDS_BIGENDIAN
+
+        /* pkt->data is GGGRRRR BBBBBGGG
+         * and we need RRRRRGGG GGGBBBBB
+         * for PIX_FMT_RGB565 so here we
+         * just swap bytes as they come
+         */
+
+        for(i=0;i<mtv->img_segment_size/2;i++)
+            *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
+#endif
+        mtv->audio_packet_count = 1;
+        pkt->stream_index = VIDEO_SID;
+    }
+
+    return(ret);
+}
+
+AVInputFormat mtv_demuxer = {
+    "MTV",
+    "MTV format",
+    sizeof(MTVDemuxContext),
+    mtv_probe,
+    mtv_read_header,
+    mtv_read_packet,
+};