FFmpeg/libavformat/rtpenc_jpeg.c
Yeoh, Hoong Tee da4b2549c6 lavf/rtpenc_jpeg: Retrieve sampling factor from SOF0
In ff_rtp_send_jpeg, the type is defined based on PIX_FMT and
color-range parsed in. There is limitation on current design
where need to include support newly introduced PIX_FMT such as
AV_PIX_FMT_QSV and there might be more and more in future. Hence,
retrive the sampling factor from SOF0 in JPEG compressed header
directly. This introduces flexibility to handle different type of
new codec introduced in future.

Signed-off-by: Yeoh, Hoong Tee <hoong.tee.yeoh@intel.com>
2023-06-20 09:52:43 +08:00

239 lines
8.1 KiB
C

/*
* RTP JPEG-compressed video Packetizer, RFC 2435
* Copyright (c) 2012 Samuel Pitoiset
*
* 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 "libavcodec/bytestream.h"
#include "libavcodec/mjpeg.h"
#include "libavcodec/jpegtables.h"
#include "libavutil/intreadwrite.h"
#include "rtpenc.h"
void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
{
RTPMuxContext *s = s1->priv_data;
const uint8_t *qtables[4] = { NULL };
int nb_qtables = 0;
uint8_t type = 2; /* initialized non-0/1 value for RTP/JPEG type check*/
uint8_t w, h;
uint8_t *p;
int off = 0; /* fragment offset of the current JPEG frame */
int len;
int i;
int default_huffman_tables = 0;
s->buf_ptr = s->buf;
s->timestamp = s->cur_timestamp;
/* convert video pixel dimensions from pixels to blocks */
w = AV_CEIL_RSHIFT(s1->streams[0]->codecpar->width, 3);
h = AV_CEIL_RSHIFT(s1->streams[0]->codecpar->height, 3);
/* preparse the header for getting some info */
for (i = 0; i < size; i++) {
if (buf[i] != 0xff)
continue;
if (buf[i + 1] == DQT) {
int tables, j;
if (buf[i + 4] & 0xF0)
av_log(s1, AV_LOG_WARNING,
"Only 8-bit precision is supported.\n");
/* a quantization table is 64 bytes long */
tables = AV_RB16(&buf[i + 2]) / 65;
if (i + 5 + tables * 65 > size) {
av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n");
return;
}
if (nb_qtables + tables > 4) {
av_log(s1, AV_LOG_ERROR, "Invalid number of quantisation tables\n");
return;
}
for (j = 0; j < tables; j++)
qtables[nb_qtables + j] = buf + i + 5 + j * 65;
nb_qtables += tables;
} else if (buf[i + 1] == SOF0) {
if (buf[i + 14] != 17 || buf[i + 17] != 17) {
av_log(s1, AV_LOG_ERROR,
"Only 1x1 chroma blocks are supported. Aborted!\n");
return;
}
/*
* Find out the sampling factor in SOF0.
* In SOF0, hsample/vsample is inserted in form of (2<<4) | (type ? 2 : 1).
* First 4-bit is hsample while Last 4-bit is vsample.
*/
/* Luma channel sampling factor in 4:2:2 chroma subsampling are 2x1 */
if (buf[i + 11] == 33) {
type = 0;
/* Luma channel sampling factor in 4:2:0 chroma subsampling are 2x2 */
} else if (buf[i + 11] == 34) {
type = 1;
} else {
av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n");
return;
}
} else if (buf[i + 1] == DHT) {
int dht_size = AV_RB16(&buf[i + 2]);
default_huffman_tables |= 1 << 4;
i += 3;
dht_size -= 2;
if (i + dht_size >= size)
continue;
while (dht_size > 0)
switch (buf[i + 1]) {
case 0x00:
if ( dht_size >= 29
&& !memcmp(buf + i + 2, ff_mjpeg_bits_dc_luminance + 1, 16)
&& !memcmp(buf + i + 18, ff_mjpeg_val_dc, 12)) {
default_huffman_tables |= 1;
i += 29;
dht_size -= 29;
} else {
i += dht_size;
dht_size = 0;
}
break;
case 0x01:
if ( dht_size >= 29
&& !memcmp(buf + i + 2, ff_mjpeg_bits_dc_chrominance + 1, 16)
&& !memcmp(buf + i + 18, ff_mjpeg_val_dc, 12)) {
default_huffman_tables |= 1 << 1;
i += 29;
dht_size -= 29;
} else {
i += dht_size;
dht_size = 0;
}
break;
case 0x10:
if ( dht_size >= 179
&& !memcmp(buf + i + 2, ff_mjpeg_bits_ac_luminance + 1, 16)
&& !memcmp(buf + i + 18, ff_mjpeg_val_ac_luminance, 162)) {
default_huffman_tables |= 1 << 2;
i += 179;
dht_size -= 179;
} else {
i += dht_size;
dht_size = 0;
}
break;
case 0x11:
if ( dht_size >= 179
&& !memcmp(buf + i + 2, ff_mjpeg_bits_ac_chrominance + 1, 16)
&& !memcmp(buf + i + 18, ff_mjpeg_val_ac_chrominance, 162)) {
default_huffman_tables |= 1 << 3;
i += 179;
dht_size -= 179;
} else {
i += dht_size;
dht_size = 0;
}
break;
default:
i += dht_size;
dht_size = 0;
continue;
}
} else if (buf[i + 1] == SOS) {
/* SOS is last marker in the header */
i += AV_RB16(&buf[i + 2]) + 2;
if (i > size) {
av_log(s1, AV_LOG_ERROR,
"Insufficient data. Aborted!\n");
return;
}
break;
}
}
/* Check validity of RTP/JPEG type */
if (type != 0 && type != 1) {
av_log(s1, AV_LOG_ERROR,
"Invalid RTP/JPEG type\n");
return;
}
if (default_huffman_tables && default_huffman_tables != 31) {
av_log(s1, AV_LOG_ERROR,
"RFC 2435 requires standard Huffman tables for jpeg\n");
return;
}
if (nb_qtables && nb_qtables != 2)
av_log(s1, AV_LOG_WARNING,
"RFC 2435 suggests two quantization tables, %d provided\n",
nb_qtables);
/* skip JPEG header */
buf += i;
size -= i;
for (i = size - 2; i >= 0; i--) {
if (buf[i] == 0xff && buf[i + 1] == EOI) {
/* Remove the EOI marker */
size = i;
break;
}
}
p = s->buf_ptr;
while (size > 0) {
int hdr_size = 8;
if (off == 0 && nb_qtables)
hdr_size += 4 + 64 * nb_qtables;
/* payload max in one packet */
len = FFMIN(size, s->max_payload_size - hdr_size);
/* set main header */
bytestream_put_byte(&p, 0);
bytestream_put_be24(&p, off);
bytestream_put_byte(&p, type);
bytestream_put_byte(&p, 255);
bytestream_put_byte(&p, w);
bytestream_put_byte(&p, h);
if (off == 0 && nb_qtables) {
/* set quantization tables header */
bytestream_put_byte(&p, 0);
bytestream_put_byte(&p, 0);
bytestream_put_be16(&p, 64 * nb_qtables);
for (i = 0; i < nb_qtables; i++)
bytestream_put_buffer(&p, qtables[i], 64);
}
/* copy payload data */
memcpy(p, buf, len);
/* marker bit is last packet in frame */
ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len);
buf += len;
size -= len;
off += len;
p = s->buf;
}
}