133 lines
4.1 KiB
C
Executable file
133 lines
4.1 KiB
C
Executable file
/*
|
|
* 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 ((err = av_new_packet(pkt, len)) < 0) {
|
|
av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
|
|
return err;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
const 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,
|
|
};
|