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/*
* RTP Depacketization of RAW video (TR-03)
* Copyright (c) 2016 Savoir-faire Linux, Inc
*
* 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
*/
/* Development sponsored by CBC/Radio-Canada */
#include "avio_internal.h"
#include "rtpdec_formats.h"
#include "libavutil/avstring.h"
#include "libavutil/pixdesc.h"
struct PayloadContext {
char *sampling;
int depth;
int width;
int height;
uint8_t *frame;
unsigned int frame_size;
unsigned int pgroup; /* size of the pixel group in bytes */
unsigned int xinc;
uint32_t timestamp;
};
static int rfc4175_parse_format(AVStream *stream, PayloadContext *data)
{
enum AVPixelFormat pixfmt = AV_PIX_FMT_NONE;
int tag = 0;
const AVPixFmtDescriptor *desc;
if (!strncmp(data->sampling, "YCbCr-4:2:2", 11)) {
tag = MKTAG('U', 'Y', 'V', 'Y');
data->xinc = 2;
if (data->depth == 8) {
data->pgroup = 4;
pixfmt = AV_PIX_FMT_UYVY422;
} else if (data->depth == 10) {
data->pgroup = 5;
pixfmt = AV_PIX_FMT_YUV422P10;
} else {
return AVERROR_INVALIDDATA;
}
} else {
return AVERROR_INVALIDDATA;
}
desc = av_pix_fmt_desc_get(pixfmt);
stream->codecpar->format = pixfmt;
stream->codecpar->codec_tag = tag;
stream->codecpar->bits_per_coded_sample = av_get_bits_per_pixel(desc);
data->frame_size = data->width * data->height * data->pgroup / data->xinc;
return 0;
}
static int rfc4175_parse_fmtp(AVFormatContext *s, AVStream *stream,
PayloadContext *data, const char *attr,
const char *value)
{
if (!strncmp(attr, "width", 5))
data->width = atoi(value);
else if (!strncmp(attr, "height", 6))
data->height = atoi(value);
else if (!strncmp(attr, "sampling", 8))
data->sampling = av_strdup(value);
else if (!strncmp(attr, "depth", 5))
data->depth = atoi(value);
return 0;
}
static int rfc4175_parse_sdp_line(AVFormatContext *s, int st_index,
PayloadContext *data, const char *line)
{
const char *p;
if (st_index < 0)
return 0;
if (av_strstart(line, "fmtp:", &p)) {
AVStream *stream = s->streams[st_index];
int ret = ff_parse_fmtp(s, stream, data, p, rfc4175_parse_fmtp);
if (ret < 0)
return ret;
if (!data->sampling || !data->depth || !data->width || !data->height)
return -1;
stream->codecpar->width = data->width;
stream->codecpar->height = data->height;
ret = rfc4175_parse_format(stream, data);
av_freep(&data->sampling);
return ret;
}
return 0;
}
static int rfc4175_finalize_packet(PayloadContext *data, AVPacket *pkt,
int stream_index)
{
int ret;
pkt->stream_index = stream_index;
ret = av_packet_from_data(pkt, data->frame, data->frame_size);
if (ret < 0) {
av_freep(&data->frame);
}
data->frame = NULL;
return ret;
}
static int rfc4175_handle_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t * buf, int len,
uint16_t seq, int flags)
{
int length, line, offset, cont;
const uint8_t *headers = buf + 2; /* skip extended seqnum */
const uint8_t *payload = buf + 2;
int payload_len = len - 2;
int missed_last_packet = 0;
uint8_t *dest;
if (*timestamp != data->timestamp) {
if (data->frame) {
/*
* if we're here, it means that two RTP packets didn't have the
* same timestamp, which is a sign that they were packets from two
* different frames, but we didn't get the flag RTP_FLAG_MARKER on
* the first one of these frames (last packet of a frame).
* Finalize the previous frame anyway by filling the AVPacket.
*/
av_log(ctx, AV_LOG_ERROR, "Missed previous RTP Marker\n");
missed_last_packet = 1;
rfc4175_finalize_packet(data, pkt, st->index);
}
data->frame = av_malloc(data->frame_size);
data->timestamp = *timestamp;
if (!data->frame) {
av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
return AVERROR(ENOMEM);
}
}
/*
* looks for the 'Continuation bit' in scan lines' headers
* to find where data start
*/
do {
if (payload_len < 6)
return AVERROR_INVALIDDATA;
cont = payload[4] & 0x80;
payload += 6;
payload_len -= 6;
} while (cont);
/* and now iterate over every scan lines */
do {
int copy_offset;
if (payload_len < data->pgroup)
return AVERROR_INVALIDDATA;
length = (headers[0] << 8) | headers[1];
line = ((headers[2] & 0x7f) << 8) | headers[3];
offset = ((headers[4] & 0x7f) << 8) | headers[5];
cont = headers[4] & 0x80;
headers += 6;
if (!data->pgroup || length % data->pgroup)
return AVERROR_INVALIDDATA;
if (length > payload_len)
length = payload_len;
/* prevent ill-formed packets to write after buffer's end */
copy_offset = (line * data->width + offset) * data->pgroup / data->xinc;
if (copy_offset + length > data->frame_size)
return AVERROR_INVALIDDATA;
dest = data->frame + copy_offset;
memcpy(dest, payload, length);
payload += length;
payload_len -= length;
} while (cont);
if ((flags & RTP_FLAG_MARKER)) {
return rfc4175_finalize_packet(data, pkt, st->index);
} else if (missed_last_packet) {
return 0;
}
return AVERROR(EAGAIN);
}
const RTPDynamicProtocolHandler ff_rfc4175_rtp_handler = {
.enc_name = "raw",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_BITPACKED,
.priv_data_size = sizeof(PayloadContext),
.parse_sdp_a_line = rfc4175_parse_sdp_line,
.parse_packet = rfc4175_handle_packet,
};
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