making act segmenter

1 files changed, 128 insertions, 0 deletions

diff --git a/ffmpeg/libavformat/xa.c b/ffmpeg/libavformat/xa.c
new file mode 100644
index 0000000..e3d36e6
--- /dev/null
+++ b/ffmpeg/libavformat/xa.c
@@ -0,0 +1,128 @@
+/*
+ * Maxis XA (.xa) File Demuxer
+ * Copyright (c) 2008 Robert Marston
+ *
+ * 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
+ * Maxis XA File Demuxer
+ * by Robert Marston (rmarston@gmail.com)
+ * for more information on the XA audio format see
+ *   http://wiki.multimedia.cx/index.php?title=Maxis_XA
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+#include "internal.h"
+
+#define XA00_TAG MKTAG('X', 'A', 0, 0)
+#define XAI0_TAG MKTAG('X', 'A', 'I', 0)
+#define XAJ0_TAG MKTAG('X', 'A', 'J', 0)
+
+typedef struct MaxisXADemuxContext {
+    uint32_t out_size;
+    uint32_t sent_bytes;
+} MaxisXADemuxContext;
+
+static int xa_probe(AVProbeData *p)
+{
+    int channels, srate, bits_per_sample;
+    if (p->buf_size < 24)
+        return 0;
+    switch(AV_RL32(p->buf)) {
+    case XA00_TAG:
+    case XAI0_TAG:
+    case XAJ0_TAG:
+        break;
+    default:
+        return 0;
+    }
+    channels        = AV_RL16(p->buf + 10);
+    srate           = AV_RL32(p->buf + 12);
+    bits_per_sample = AV_RL16(p->buf + 22);
+    if (!channels || channels > 8 || !srate || srate > 192000 ||
+        bits_per_sample < 4 || bits_per_sample > 32)
+        return 0;
+    return AVPROBE_SCORE_MAX/2;
+}
+
+static int xa_read_header(AVFormatContext *s)
+{
+    MaxisXADemuxContext *xa = s->priv_data;
+    AVIOContext *pb = s->pb;
+    AVStream *st;
+
+    /*Set up the XA Audio Decoder*/
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codec->codec_type   = AVMEDIA_TYPE_AUDIO;
+    st->codec->codec_id     = AV_CODEC_ID_ADPCM_EA_MAXIS_XA;
+    avio_skip(pb, 4);       /* Skip the XA ID */
+    xa->out_size            =  avio_rl32(pb);
+    avio_skip(pb, 2);       /* Skip the tag */
+    st->codec->channels     = avio_rl16(pb);
+    st->codec->sample_rate  = avio_rl32(pb);
+    avio_skip(pb, 4);       /* Skip average byte rate */
+    avio_skip(pb, 2);       /* Skip block align */
+    avio_skip(pb, 2);       /* Skip bits-per-sample */
+
+    st->codec->bit_rate = av_clip(15LL * st->codec->channels * 8 *
+                                  st->codec->sample_rate / 28, 0, INT_MAX);
+
+    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+    st->start_time = 0;
+
+    return 0;
+}
+
+static int xa_read_packet(AVFormatContext *s,
+                          AVPacket *pkt)
+{
+    MaxisXADemuxContext *xa = s->priv_data;
+    AVStream *st = s->streams[0];
+    AVIOContext *pb = s->pb;
+    unsigned int packet_size;
+    int ret;
+
+    if (xa->sent_bytes >= xa->out_size)
+        return AVERROR_EOF;
+    /* 1 byte header and 14 bytes worth of samples * number channels per block */
+    packet_size = 15*st->codec->channels;
+
+    ret = av_get_packet(pb, pkt, packet_size);
+    if(ret < 0)
+        return ret;
+
+    pkt->stream_index = st->index;
+    xa->sent_bytes += packet_size;
+    pkt->duration = 28;
+
+    return ret;
+}
+
+AVInputFormat ff_xa_demuxer = {
+    .name           = "xa",
+    .long_name      = NULL_IF_CONFIG_SMALL("Maxis XA"),
+    .priv_data_size = sizeof(MaxisXADemuxContext),
+    .read_probe     = xa_probe,
+    .read_header    = xa_read_header,
+    .read_packet    = xa_read_packet,
+};