ffmpeg/libavformat/rtpdec_dv.c

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/*
* RTP parser for DV payload format (RFC 6469)
* Copyright (c) 2015 Thomas Volkert <thomas@homer-conferencing.com>
*
* 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/avstring.h"
#include "libavcodec/bytestream.h"
#include "rtpdec_formats.h"
struct PayloadContext {
AVIOContext *buf;
uint32_t timestamp;
int bundled_audio;
};
static av_cold PayloadContext *dv_new_context(void)
{
return av_mallocz(sizeof(PayloadContext));
}
static void dv_free_dyn_buffer(AVIOContext **dyn_buf)
{
uint8_t *ptr_dyn_buffer;
avio_close_dyn_buf(*dyn_buf, &ptr_dyn_buffer);
av_free(ptr_dyn_buffer);
*dyn_buf = NULL;
}
static av_cold void dv_free_context(PayloadContext *data)
{
dv_free_dyn_buffer(&data->buf);
av_free(data);
}
static av_cold int dv_init(AVFormatContext *ctx, int st_index,
PayloadContext *data)
{
av_dlog(ctx, "dv_init() for stream %d\n", st_index);
if (st_index < 0)
return 0;
ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
return 0;
}
static av_cold int dv_sdp_parse_fmtp_config(AVFormatContext *s,
AVStream *stream,
PayloadContext *dv_data,
char *attr, char *value)
{
/* does the DV stream include audio? */
if (!strcmp(attr, "audio") && !strcmp(value, "bundled"))
dv_data->bundled_audio = 1;
/* extract the DV profile */
if (!strcmp(attr, "encode")) {
/* SD-VCR/525-60 */
/* SD-VCR/625-50 */
/* HD-VCR/1125-60 */
/* HD-VCR/1250-50 */
/* SDL-VCR/525-60 */
/* SDL-VCR/625-50 */
/* 314M-25/525-60 */
/* 314M-25/625-50 */
/* 314M-50/525-60 */
/* 314M-50/625-50 */
/* 370M/1080-60i */
/* 370M/1080-50i */
/* 370M/720-60p */
/* 370M/720-50p */
/* 306M/525-60 (for backward compatibility) */
/* 306M/625-50 (for backward compatibility) */
}
return 0;
}
static av_cold int dv_parse_sdp_line(AVFormatContext *ctx, int st_index,
PayloadContext *dv_data, const char *line)
{
AVStream *current_stream;
const char *sdp_line_ptr = line;
if (st_index < 0)
return 0;
current_stream = ctx->streams[st_index];
if (av_strstart(sdp_line_ptr, "fmtp:", &sdp_line_ptr)) {
return ff_parse_fmtp(ctx, current_stream, dv_data, sdp_line_ptr,
dv_sdp_parse_fmtp_config);
}
return 0;
}
static int dv_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_dv_ctx,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq,
int flags)
{
int res = 0;
/* drop data of previous packets in case of non-continuous (lossy) packet stream */
if (rtp_dv_ctx->buf && rtp_dv_ctx->timestamp != *timestamp) {
dv_free_dyn_buffer(&rtp_dv_ctx->buf);
}
/* sanity check for size of input packet: 1 byte payload at least */
if (len < 1) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/DV packet, got %d bytes\n", len);
return AVERROR_INVALIDDATA;
}
/* start frame buffering with new dynamic buffer */
if (!rtp_dv_ctx->buf) {
res = avio_open_dyn_buf(&rtp_dv_ctx->buf);
if (res < 0)
return res;
/* update the timestamp in the frame packet with the one from the RTP packet */
rtp_dv_ctx->timestamp = *timestamp;
}
/* write the fragment to the dyn. buffer */
avio_write(rtp_dv_ctx->buf, buf, len);
/* RTP marker bit means: last fragment of current frame was received;
otherwise, an additional fragment is needed for the current frame */
if (!(flags & RTP_FLAG_MARKER))
return AVERROR(EAGAIN);
/* close frame buffering and create resulting A/V packet */
res = ff_rtp_finalize_packet(pkt, &rtp_dv_ctx->buf, st->index);
if (res < 0)
return res;
return 0;
}
RTPDynamicProtocolHandler ff_dv_dynamic_handler = {
.enc_name = "DV",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_DVVIDEO,
.init = dv_init,
.parse_sdp_a_line = dv_parse_sdp_line,
.alloc = dv_new_context,
.free = dv_free_context,
.parse_packet = dv_handle_packet
};