ffmpeg-2.8.5

git-svn-id: svn://kolibrios.org@6147 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/ffmpeg/ffmpeg-2.8/libavformat/rtpdec_ac3.c

@@ -0,0 +1,133 @@
+/*
+ * RTP parser for AC3 payload format (RFC 4184)
+ * Copyright (c) 2015 Gilles Chanteperdrix <gch@xenomai.org>
+ *
+ * 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 "avio_internal.h"
+#include "rtpdec_formats.h"
+
+#define RTP_AC3_PAYLOAD_HEADER_SIZE 2
+
+struct PayloadContext {
+    unsigned nr_frames;
+    unsigned last_frame;
+    uint32_t timestamp;
+    AVIOContext *fragment;
+};
+
+static void ac3_close_context(PayloadContext *data)
+{
+    ffio_free_dyn_buf(&data->fragment);
+}
+
+static int ac3_handle_packet(AVFormatContext *ctx, PayloadContext *data,
+                             AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                             const uint8_t *buf, int len, uint16_t seq,
+                             int flags)
+{
+    unsigned frame_type;
+    unsigned nr_frames;
+    int err;
+
+    if (len < RTP_AC3_PAYLOAD_HEADER_SIZE + 1) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len);
+        return AVERROR_INVALIDDATA;
+    }
+
+    frame_type = buf[0] & 0x3;
+    nr_frames = buf[1];
+    buf += RTP_AC3_PAYLOAD_HEADER_SIZE;
+    len -= RTP_AC3_PAYLOAD_HEADER_SIZE;
+
+    switch (frame_type) {
+    case 0: /* One or more complete frames */
+        if (!nr_frames) {
+            av_log(ctx, AV_LOG_ERROR, "Invalid AC3 packet data\n");
+            return AVERROR_INVALIDDATA;
+        }
+        if (av_new_packet(pkt, len)) {
+            av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
+            return AVERROR(ENOMEM);
+        }
+
+        pkt->stream_index = st->index;
+        memcpy(pkt->data, buf, len);
+        return 0;
+
+    case 1:
+    case 2: /* First fragment */
+        ffio_free_dyn_buf(&data->fragment);
+
+        data->last_frame = 1;
+        data->nr_frames = nr_frames;
+        err = avio_open_dyn_buf(&data->fragment);
+        if (err < 0)
+            return err;
+
+        avio_write(data->fragment, buf, len);
+        data->timestamp = *timestamp;
+        return AVERROR(EAGAIN);
+
+    case 3: /* Fragment other than first */
+        if (!data->fragment) {
+            av_log(ctx, AV_LOG_WARNING,
+                   "Received packet without a start fragment; dropping.\n");
+            return AVERROR(EAGAIN);
+        }
+        if (nr_frames != data->nr_frames ||
+            data->timestamp != *timestamp) {
+            ffio_free_dyn_buf(&data->fragment);
+            av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        avio_write(data->fragment, buf, len);
+        data->last_frame++;
+    }
+
+    if (!(flags & RTP_FLAG_MARKER))
+        return AVERROR(EAGAIN);
+
+    if (data->last_frame != data->nr_frames) {
+        ffio_free_dyn_buf(&data->fragment);
+        av_log(ctx, AV_LOG_ERROR, "Missed %d packets\n",
+               data->nr_frames - data->last_frame);
+        return AVERROR_INVALIDDATA;
+    }
+
+    err = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
+    if (err < 0) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Error occurred when getting fragment buffer.\n");
+        return err;
+    }
+
+    return 0;
+}
+
+RTPDynamicProtocolHandler ff_ac3_dynamic_handler = {
+    .enc_name           = "ac3",
+    .codec_type         = AVMEDIA_TYPE_AUDIO,
+    .codec_id           = AV_CODEC_ID_AC3,
+    .need_parsing       = AVSTREAM_PARSE_FULL,
+    .priv_data_size     = sizeof(PayloadContext),
+    .close              = ac3_close_context,
+    .parse_packet       = ac3_handle_packet,
+};