CRYO APC demuxer

patch by Anssi Hannula, anssi.hannula gmail com

Originally committed as revision 8656 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 93 insertions, 0 deletions

diff --git a/libavformat/apc.c b/libavformat/apc.c
new file mode 100644
index 0000000000..a937b1d8d7
--- /dev/null
+++ b/libavformat/apc.c
@@ -0,0 +1,93 @@
+/*
+ * CRYO APC audio format demuxer
+ * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
+ *
+ * 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
+ */
+
+#include "avformat.h"
+#include "string.h"
+
+static int apc_probe(AVProbeData *p)
+{
+    if (p->buf_size < 8)
+        return 0;
+
+    if (!strncmp(p->buf, "CRYO_APC", 8))
+        return AVPROBE_SCORE_MAX;
+
+    return 0;
+}
+
+static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    ByteIOContext *pb = &s->pb;
+    AVStream *st;
+
+    get_le32(pb); /* CRYO */
+    get_le32(pb); /* _APC */
+    get_le32(pb); /* 1.20 */
+
+    st = av_new_stream(s, 0);
+    if (!st)
+        return AVERROR_NOMEM;
+
+    st->codec->codec_type = CODEC_TYPE_AUDIO;
+    st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
+
+    get_le32(pb); /* number of samples */
+    st->codec->sample_rate = get_le32(pb);
+
+    st->codec->extradata_size = 2 * 4;
+    st->codec->extradata = av_malloc(st->codec->extradata_size +
+                                     FF_INPUT_BUFFER_PADDING_SIZE);
+    if (!st->codec->extradata)
+        return AVERROR_NOMEM;
+
+    /* initial predictor values for adpcm decoder */
+    get_buffer(pb, st->codec->extradata, 2 * 4);
+
+    st->codec->channels = 1;
+    if (get_le32(pb))
+        st->codec->channels = 2;
+
+    st->codec->bits_per_sample = 4;
+    st->codec->bit_rate = st->codec->bits_per_sample * st->codec->channels
+                          * st->codec->sample_rate;
+    st->codec->block_align = 1;
+
+    return 0;
+}
+
+#define MAX_READ_SIZE 4096
+
+static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    if (av_get_packet(&s->pb, pkt, MAX_READ_SIZE) <= 0)
+        return AVERROR_IO;
+    pkt->stream_index = 0;
+    return 0;
+}
+
+AVInputFormat apc_demuxer = {
+    "apc",
+    "CRYO APC format",
+    0,
+    apc_probe,
+    apc_read_header,
+    apc_read_packet,
+};