1 files changed, 100 insertions, 0 deletions
diff --git a/ffmpeg/libavformat/gsmdec.c b/ffmpeg/libavformat/gsmdec.c
new file mode 100644
index 0000000..9899266
--- /dev/null
+++ b/ffmpeg/libavformat/gsmdec.c
@@ -0,0 +1,100 @@
+/*
+ * RAW GSM demuxer
+ * Copyright (c) 2011 Justin Ruggles
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/opt.h"
+#include "avformat.h"
+#include "internal.h"
+
+#define GSM_BLOCK_SIZE    33
+#define GSM_BLOCK_SAMPLES 160
+#define GSM_SAMPLE_RATE   8000
+
+typedef struct {
+    AVClass *class;
+    int sample_rate;
+} GSMDemuxerContext;
+
+static int gsm_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    int ret, size;
+
+    size = GSM_BLOCK_SIZE;
+
+    pkt->pos = avio_tell(s->pb);
+    pkt->stream_index = 0;
+
+    ret = av_get_packet(s->pb, pkt, size);
+    if (ret < GSM_BLOCK_SIZE) {
+        av_free_packet(pkt);
+        return ret < 0 ? ret : AVERROR(EIO);
+    }
+    pkt->duration = 1;
+    pkt->pts      = pkt->pos / GSM_BLOCK_SIZE;
+
+    return 0;
+}
+
+static int gsm_read_header(AVFormatContext *s)
+{
+    GSMDemuxerContext *c = s->priv_data;
+    AVStream *st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
+    st->codec->codec_id    = s->iformat->raw_codec_id;
+    st->codec->channels    = 1;
+    st->codec->channel_layout = AV_CH_LAYOUT_MONO;
+    st->codec->sample_rate = c->sample_rate;
+    st->codec->bit_rate    = GSM_BLOCK_SIZE * 8 * c->sample_rate / GSM_BLOCK_SAMPLES;
+
+    avpriv_set_pts_info(st, 64, GSM_BLOCK_SAMPLES, GSM_SAMPLE_RATE);
+
+    return 0;
+}
+
+static const AVOption options[] = {
+    { "sample_rate", "", offsetof(GSMDemuxerContext, sample_rate),
+       AV_OPT_TYPE_INT, {.i64 = GSM_SAMPLE_RATE}, 1, INT_MAX / GSM_BLOCK_SIZE,
+       AV_OPT_FLAG_DECODING_PARAM },
+    { NULL },
+};
+
+static const AVClass class = {
+    .class_name = "gsm demuxer",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+AVInputFormat ff_gsm_demuxer = {
+    .name           = "gsm",
+    .long_name      = NULL_IF_CONFIG_SMALL("raw GSM"),
+    .priv_data_size = sizeof(GSMDemuxerContext),
+    .read_header    = gsm_read_header,
+    .read_packet    = gsm_read_packet,
+    .flags          = AVFMT_GENERIC_INDEX,
+    .extensions     = "gsm",
+    .raw_codec_id   = AV_CODEC_ID_GSM,
+    .priv_class     = &class,
+};