rtpdec: Add a depacketizer for iLBC

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 73 insertions, 0 deletions

diff --git a/libavformat/rtpdec_ilbc.c b/libavformat/rtpdec_ilbc.c
new file mode 100644
index 0000000000..7159dcf6be
--- /dev/null
+++ b/libavformat/rtpdec_ilbc.c
@@ -0,0 +1,73 @@
+/*
+ * RTP iLBC Depacketizer, RFC 3952
+ * Copyright (c) 2012 Martin Storsjo
+ *
+ * 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 "avformat.h"
+#include "rtpdec_formats.h"
+#include "libavutil/avstring.h"
+
+static int ilbc_parse_fmtp(AVStream *stream, PayloadContext *data,
+                           char *attr, char *value)
+{
+    if (!strcmp(attr, "mode")) {
+        int mode = atoi(value);
+        switch (mode) {
+        case 20:
+            stream->codec->block_align = 38;
+            break;
+        case 30:
+            stream->codec->block_align = 50;
+            break;
+        default:
+            av_log(NULL, AV_LOG_ERROR, "Unsupported iLBC mode %d\n", mode);
+            return AVERROR(EINVAL);
+        }
+    }
+    return 0;
+}
+
+static int ilbc_parse_sdp_line(AVFormatContext *s, int st_index,
+                               PayloadContext *data, const char *line)
+{
+    const char *p;
+    AVStream *st;
+
+    if (st_index < 0)
+        return 0;
+    st = s->streams[st_index];
+
+    if (av_strstart(line, "fmtp:", &p)) {
+        int ret = ff_parse_fmtp(st, data, p, ilbc_parse_fmtp);
+        if (ret < 0)
+            return ret;
+        if (!st->codec->block_align) {
+            av_log(s, AV_LOG_ERROR, "No iLBC mode set\n");
+            return AVERROR(EINVAL);
+        }
+    }
+    return 0;
+}
+
+RTPDynamicProtocolHandler ff_ilbc_dynamic_handler = {
+    .enc_name         = "iLBC",
+    .codec_type       = AVMEDIA_TYPE_AUDIO,
+    .codec_id         = CODEC_ID_ILBC,
+    .parse_sdp_a_line = ilbc_parse_sdp_line,
+};