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FFmpeg/libavformat/rtpdec_jpeg.c

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/*
* RTP JPEG-compressed Video Depacketizer, RFC 2435
* Copyright (c) 2012 Samuel Pitoiset
*
* 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 "avformat.h"
#include "rtpdec.h"
#include "rtpdec_formats.h"
#include "libavutil/intreadwrite.h"
#include "libavcodec/mjpeg.h"
#include "libavcodec/bytestream.h"
/**
* RTP/JPEG specific private data.
*/
struct PayloadContext {
AVIOContext *frame; ///< current frame buffer
uint32_t timestamp; ///< current frame timestamp
int hdr_size; ///< size of the current frame header
uint8_t qtables[128][128];
uint8_t qtables_len[128];
};
static const uint8_t default_quantizers[128] = {
/* luma table */
16, 11, 12, 14, 12, 10, 16, 14,
13, 14, 18, 17, 16, 19, 24, 40,
26, 24, 22, 22, 24, 49, 35, 37,
29, 40, 58, 51, 61, 60, 57, 51,
56, 55, 64, 72, 92, 78, 64, 68,
87, 69, 55, 56, 80, 109, 81, 87,
95, 98, 103, 104, 103, 62, 77, 113,
121, 112, 100, 120, 92, 101, 103, 99,
/* chroma table */
17, 18, 18, 24, 21, 24, 47, 26,
26, 47, 99, 66, 56, 66, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
};
static PayloadContext *jpeg_new_context(void)
{
return av_mallocz(sizeof(PayloadContext));
}
static inline void free_frame_if_needed(PayloadContext *jpeg)
{
if (jpeg->frame) {
uint8_t *p;
avio_close_dyn_buf(jpeg->frame, &p);
av_free(p);
jpeg->frame = NULL;
}
}
static void jpeg_free_context(PayloadContext *jpeg)
{
free_frame_if_needed(jpeg);
av_free(jpeg);
}
static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
int table_id, const uint8_t *bits_table,
const uint8_t *value_table)
{
int i, n = 0;
bytestream2_put_byte(p, table_class << 4 | table_id);
for (i = 1; i <= 16; i++) {
n += bits_table[i];
bytestream2_put_byte(p, bits_table[i]);
}
for (i = 0; i < n; i++) {
bytestream2_put_byte(p, value_table[i]);
}
return n + 17;
}
static void jpeg_put_marker(PutByteContext *pbc, int code)
{
bytestream2_put_byte(pbc, 0xff);
bytestream2_put_byte(pbc, code);
}
static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
uint32_t h, const uint8_t *qtable, int nb_qtable)
{
PutByteContext pbc;
uint8_t *dht_size_ptr;
int dht_size, i;
bytestream2_init_writer(&pbc, buf, size);
/* Convert from blocks to pixels. */
w <<= 3;
h <<= 3;
/* SOI */
jpeg_put_marker(&pbc, SOI);
/* JFIF header */
jpeg_put_marker(&pbc, APP0);
bytestream2_put_be16(&pbc, 16);
bytestream2_put_buffer(&pbc, "JFIF", 5);
bytestream2_put_be16(&pbc, 0x0201);
bytestream2_put_byte(&pbc, 0);
bytestream2_put_be16(&pbc, 1);
bytestream2_put_be16(&pbc, 1);
bytestream2_put_byte(&pbc, 0);
bytestream2_put_byte(&pbc, 0);
/* DQT */
jpeg_put_marker(&pbc, DQT);
bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
for (i = 0; i < nb_qtable; i++) {
bytestream2_put_byte(&pbc, i);
/* Each table is an array of 64 values given in zig-zag
* order, identical to the format used in a JFIF DQT
* marker segment. */
bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
}
/* DHT */
jpeg_put_marker(&pbc, DHT);
dht_size_ptr = pbc.buffer;
bytestream2_put_be16(&pbc, 0);
dht_size = 2;
dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
avpriv_mjpeg_val_dc);
dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
avpriv_mjpeg_val_dc);
dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
avpriv_mjpeg_val_ac_luminance);
dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
avpriv_mjpeg_val_ac_chrominance);
AV_WB16(dht_size_ptr, dht_size);
/* SOF0 */
jpeg_put_marker(&pbc, SOF0);
bytestream2_put_be16(&pbc, 17); /* size */
bytestream2_put_byte(&pbc, 8); /* bits per component */
bytestream2_put_be16(&pbc, h);
bytestream2_put_be16(&pbc, w);
bytestream2_put_byte(&pbc, 3); /* number of components */
bytestream2_put_byte(&pbc, 1); /* component number */
bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
bytestream2_put_byte(&pbc, 0); /* matrix number */
bytestream2_put_byte(&pbc, 2); /* component number */
bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
bytestream2_put_byte(&pbc, 3); /* component number */
bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
/* SOS */
jpeg_put_marker(&pbc, SOS);
bytestream2_put_be16(&pbc, 12);
bytestream2_put_byte(&pbc, 3);
bytestream2_put_byte(&pbc, 1);
bytestream2_put_byte(&pbc, 0);
bytestream2_put_byte(&pbc, 2);
bytestream2_put_byte(&pbc, 17);
bytestream2_put_byte(&pbc, 3);
bytestream2_put_byte(&pbc, 17);
bytestream2_put_byte(&pbc, 0);
bytestream2_put_byte(&pbc, 63);
bytestream2_put_byte(&pbc, 0);
/* Return the length in bytes of the JPEG header. */
return bytestream2_tell_p(&pbc);
}
static void create_default_qtables(uint8_t *qtables, uint8_t q)
{
int factor = q;
int i;
factor = av_clip(q, 1, 99);
if (q < 50)
q = 5000 / factor;
else
q = 200 - factor * 2;
for (i = 0; i < 128; i++) {
int val = (default_quantizers[i] * q + 50) / 100;
/* Limit the quantizers to 1 <= q <= 255. */
val = av_clip(val, 1, 255);
qtables[i] = val;
}
}
static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, int flags)
{
uint8_t type, q, width, height;
const uint8_t *qtables = NULL;
uint16_t qtable_len;
uint32_t off;
int ret;
if (len < 8) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
/* Parse the main JPEG header. */
off = AV_RB24(buf + 1); /* fragment byte offset */
type = AV_RB8(buf + 4); /* id of jpeg decoder params */
q = AV_RB8(buf + 5); /* quantization factor (or table id) */
width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
buf += 8;
len -= 8;
/* Parse the restart marker header. */
if (type > 63) {
av_log(ctx, AV_LOG_ERROR,
"Unimplemented RTP/JPEG restart marker header.\n");
return AVERROR_PATCHWELCOME;
}
if (type > 1) {
av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
return AVERROR_PATCHWELCOME;
}
/* Parse the quantization table header. */
if (off == 0) {
/* Start of JPEG data packet. */
uint8_t new_qtables[128];
uint8_t hdr[1024];
if (q > 127) {
uint8_t precision;
if (len < 4) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
/* The first byte is reserved for future use. */
precision = AV_RB8(buf + 1); /* size of coefficients */
qtable_len = AV_RB16(buf + 2); /* length in bytes */
buf += 4;
len -= 4;
if (precision)
av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
if (qtable_len > 0) {
if (len < qtable_len) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
return AVERROR_INVALIDDATA;
}
qtables = buf;
buf += qtable_len;
len -= qtable_len;
if (q < 255) {
if (jpeg->qtables_len[q - 128] &&
(jpeg->qtables_len[q - 128] != qtable_len ||
memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
av_log(ctx, AV_LOG_WARNING,
"Quantization tables for q=%d changed\n", q);
} else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
memcpy(&jpeg->qtables[q - 128][0], qtables,
qtable_len);
jpeg->qtables_len[q - 128] = qtable_len;
}
}
} else {
if (q == 255) {
av_log(ctx, AV_LOG_ERROR,
"Invalid RTP/JPEG packet. Quantization tables not found.\n");
return AVERROR_INVALIDDATA;
}
if (!jpeg->qtables_len[q - 128]) {
av_log(ctx, AV_LOG_ERROR,
"No quantization tables known for q=%d yet.\n", q);
return AVERROR_INVALIDDATA;
}
qtables = &jpeg->qtables[q - 128][0];
qtable_len = jpeg->qtables_len[q - 128];
}
} else { /* q <= 127 */
if (q == 0 || q > 99) {
av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
return AVERROR_INVALIDDATA;
}
create_default_qtables(new_qtables, q);
qtables = new_qtables;
qtable_len = sizeof(new_qtables);
}
/* Skip the current frame in case of the end packet
* has been lost somewhere. */
free_frame_if_needed(jpeg);
if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
return ret;
jpeg->timestamp = *timestamp;
/* Generate a frame and scan headers that can be prepended to the
* RTP/JPEG data payload to produce a JPEG compressed image in
* interchange format. */
jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
height, qtables,
qtable_len / 64);
/* Copy JPEG header to frame buffer. */
avio_write(jpeg->frame, hdr, jpeg->hdr_size);
}
if (!jpeg->frame) {
av_log(ctx, AV_LOG_ERROR,
"Received packet without a start chunk; dropping frame.\n");
return AVERROR(EAGAIN);
}
if (jpeg->timestamp != *timestamp) {
/* Skip the current frame if timestamp is incorrect.
* A start packet has been lost somewhere. */
free_frame_if_needed(jpeg);
av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
return AVERROR_INVALIDDATA;
}
if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
av_log(ctx, AV_LOG_ERROR,
"Missing packets; dropping frame.\n");
return AVERROR(EAGAIN);
}
/* Copy data to frame buffer. */
avio_write(jpeg->frame, buf, len);
if (flags & RTP_FLAG_MARKER) {
/* End of JPEG data packet. */
uint8_t buf[2] = { 0xff, EOI };
/* Put EOI marker. */
avio_write(jpeg->frame, buf, sizeof(buf));
/* Prepare the JPEG packet. */
if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error occured when getting frame buffer.\n");
return ret;
}
return 0;
}
return AVERROR(EAGAIN);
}
RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
.enc_name = "JPEG",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_MJPEG,
.alloc = jpeg_new_context,
.free = jpeg_free_context,
.parse_packet = jpeg_parse_packet,
.static_payload_id = 26,
};