mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
195 lines
7.3 KiB
C
195 lines
7.3 KiB
C
/*
|
|
* RTP packetization for H.263 video
|
|
* Copyright (c) 2012 Martin Storsjo
|
|
*
|
|
* 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 "rtpenc.h"
|
|
#include "libavcodec/put_bits.h"
|
|
#include "libavcodec/get_bits.h"
|
|
|
|
struct H263Info {
|
|
int src;
|
|
int i;
|
|
int u;
|
|
int s;
|
|
int a;
|
|
int pb;
|
|
int tr;
|
|
};
|
|
|
|
struct H263State {
|
|
int gobn;
|
|
int mba;
|
|
int hmv1, vmv1, hmv2, vmv2;
|
|
int quant;
|
|
};
|
|
|
|
static void send_mode_a(AVFormatContext *s1, const struct H263Info *info,
|
|
const uint8_t *buf, int len, int ebits, int m)
|
|
{
|
|
RTPMuxContext *s = s1->priv_data;
|
|
PutBitContext pb;
|
|
|
|
init_put_bits(&pb, s->buf, 32);
|
|
put_bits(&pb, 1, 0); /* F - 0, mode A */
|
|
put_bits(&pb, 1, 0); /* P - 0, normal I/P */
|
|
put_bits(&pb, 3, 0); /* SBIT - 0 bits */
|
|
put_bits(&pb, 3, ebits); /* EBIT */
|
|
put_bits(&pb, 3, info->src); /* SRC - source format */
|
|
put_bits(&pb, 1, info->i); /* I - inter/intra */
|
|
put_bits(&pb, 1, info->u); /* U - unrestricted motion vector */
|
|
put_bits(&pb, 1, info->s); /* S - syntax-baesd arithmetic coding */
|
|
put_bits(&pb, 1, info->a); /* A - advanced prediction */
|
|
put_bits(&pb, 4, 0); /* R - reserved */
|
|
put_bits(&pb, 2, 0); /* DBQ - 0 */
|
|
put_bits(&pb, 3, 0); /* TRB - 0 */
|
|
put_bits(&pb, 8, info->tr); /* TR */
|
|
flush_put_bits(&pb);
|
|
memcpy(s->buf + 4, buf, len);
|
|
|
|
ff_rtp_send_data(s1, s->buf, len + 4, m);
|
|
}
|
|
|
|
static void send_mode_b(AVFormatContext *s1, const struct H263Info *info,
|
|
const struct H263State *state, const uint8_t *buf,
|
|
int len, int sbits, int ebits, int m)
|
|
{
|
|
RTPMuxContext *s = s1->priv_data;
|
|
PutBitContext pb;
|
|
|
|
init_put_bits(&pb, s->buf, 64);
|
|
put_bits(&pb, 1, 1); /* F - 1, mode B */
|
|
put_bits(&pb, 1, 0); /* P - 0, mode B */
|
|
put_bits(&pb, 3, sbits); /* SBIT - 0 bits */
|
|
put_bits(&pb, 3, ebits); /* EBIT - 0 bits */
|
|
put_bits(&pb, 3, info->src); /* SRC - source format */
|
|
put_bits(&pb, 5, state->quant); /* QUANT - quantizer for the first MB */
|
|
put_bits(&pb, 5, state->gobn); /* GOBN - GOB number */
|
|
put_bits(&pb, 9, state->mba); /* MBA - MB address */
|
|
put_bits(&pb, 2, 0); /* R - reserved */
|
|
put_bits(&pb, 1, info->i); /* I - inter/intra */
|
|
put_bits(&pb, 1, info->u); /* U - unrestricted motion vector */
|
|
put_bits(&pb, 1, info->s); /* S - syntax-baesd arithmetic coding */
|
|
put_bits(&pb, 1, info->a); /* A - advanced prediction */
|
|
put_bits(&pb, 7, state->hmv1); /* HVM1 - horizontal motion vector 1 */
|
|
put_bits(&pb, 7, state->vmv1); /* VMV1 - vertical motion vector 1 */
|
|
put_bits(&pb, 7, state->hmv2); /* HVM2 - horizontal motion vector 2 */
|
|
put_bits(&pb, 7, state->vmv2); /* VMV2 - vertical motion vector 2 */
|
|
flush_put_bits(&pb);
|
|
memcpy(s->buf + 8, buf, len);
|
|
|
|
ff_rtp_send_data(s1, s->buf, len + 8, m);
|
|
}
|
|
|
|
void ff_rtp_send_h263_rfc2190(AVFormatContext *s1, const uint8_t *buf, int size,
|
|
const uint8_t *mb_info, int mb_info_size)
|
|
{
|
|
RTPMuxContext *s = s1->priv_data;
|
|
int len, sbits = 0, ebits = 0;
|
|
GetBitContext gb;
|
|
struct H263Info info = { 0 };
|
|
struct H263State state = { 0 };
|
|
int mb_info_pos = 0, mb_info_count = mb_info_size / 12;
|
|
const uint8_t *buf_base = buf;
|
|
|
|
s->timestamp = s->cur_timestamp;
|
|
|
|
init_get_bits(&gb, buf, size*8);
|
|
if (get_bits(&gb, 22) == 0x20) { /* Picture Start Code */
|
|
info.tr = get_bits(&gb, 8);
|
|
skip_bits(&gb, 2); /* PTYPE start, H.261 disambiguation */
|
|
skip_bits(&gb, 3); /* Split screen, document camera, freeze picture release */
|
|
info.src = get_bits(&gb, 3);
|
|
info.i = get_bits(&gb, 1);
|
|
info.u = get_bits(&gb, 1);
|
|
info.s = get_bits(&gb, 1);
|
|
info.a = get_bits(&gb, 1);
|
|
info.pb = get_bits(&gb, 1);
|
|
}
|
|
|
|
while (size > 0) {
|
|
struct H263State packet_start_state = state;
|
|
len = FFMIN(s->max_payload_size - 8, size);
|
|
|
|
/* Look for a better place to split the frame into packets. */
|
|
if (len < size) {
|
|
const uint8_t *end = ff_h263_find_resync_marker_reverse(buf,
|
|
buf + len);
|
|
len = end - buf;
|
|
if (len == s->max_payload_size - 8) {
|
|
/* Skip mb info prior to the start of the current ptr */
|
|
while (mb_info_pos < mb_info_count) {
|
|
uint32_t pos = AV_RL32(&mb_info[12*mb_info_pos])/8;
|
|
if (pos >= buf - buf_base)
|
|
break;
|
|
mb_info_pos++;
|
|
}
|
|
/* Find the first mb info past the end pointer */
|
|
while (mb_info_pos + 1 < mb_info_count) {
|
|
uint32_t pos = AV_RL32(&mb_info[12*(mb_info_pos + 1)])/8;
|
|
if (pos >= end - buf_base)
|
|
break;
|
|
mb_info_pos++;
|
|
}
|
|
if (mb_info_pos < mb_info_count) {
|
|
const uint8_t *ptr = &mb_info[12*mb_info_pos];
|
|
/* get position in bits in the input packet at which the next info block should be used */
|
|
uint32_t bit_pos = AV_RL32(ptr);
|
|
/* get position in bytes */
|
|
uint32_t pos_next_mb_info = (bit_pos + 7)/8;
|
|
/* check if data from the next MB info block should be used */
|
|
if (pos_next_mb_info <= end - buf_base) {
|
|
state.quant = ptr[4];
|
|
state.gobn = ptr[5];
|
|
state.mba = AV_RL16(&ptr[6]);
|
|
state.hmv1 = (int8_t) ptr[8];
|
|
state.vmv1 = (int8_t) ptr[9];
|
|
state.hmv2 = (int8_t) ptr[10];
|
|
state.vmv2 = (int8_t) ptr[11];
|
|
ebits = 8 * pos_next_mb_info - bit_pos;
|
|
len = pos_next_mb_info - (buf - buf_base);
|
|
mb_info_pos++;
|
|
}
|
|
} else {
|
|
av_log(s1, AV_LOG_ERROR, "Unable to split H.263 packet, "
|
|
"use -mb_info %d or -ps 1.\n",
|
|
s->max_payload_size - 8);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (size > 2 && !buf[0] && !buf[1])
|
|
send_mode_a(s1, &info, buf, len, ebits, len == size);
|
|
else
|
|
send_mode_b(s1, &info, &packet_start_state, buf, len, sbits,
|
|
ebits, len == size);
|
|
|
|
if (ebits) {
|
|
sbits = 8 - ebits;
|
|
len--;
|
|
} else {
|
|
sbits = 0;
|
|
}
|
|
buf += len;
|
|
size -= len;
|
|
ebits = 0;
|
|
}
|
|
}
|