forked from KolibriOS/kolibrios
216 lines
6.7 KiB
C
216 lines
6.7 KiB
C
/*
|
|
* RTP H.263 Depacketizer, RFC 2190
|
|
* Copyright (c) 2012 Martin Storsjo
|
|
* Based on the GStreamer H.263 Depayloder:
|
|
* Copyright 2005 Wim Taymans
|
|
* Copyright 2007 Edward Hervey
|
|
* Copyright 2007 Nokia Corporation
|
|
* Copyright 2007 Collabora Ltd, Philippe Kalaf
|
|
* Copyright 2010 Mark Nauwelaerts
|
|
*
|
|
* 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 "rtpdec_formats.h"
|
|
#include "libavutil/attributes.h"
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "libavcodec/get_bits.h"
|
|
|
|
struct PayloadContext {
|
|
AVIOContext *buf;
|
|
uint8_t endbyte;
|
|
int endbyte_bits;
|
|
uint32_t timestamp;
|
|
int newformat;
|
|
};
|
|
|
|
static PayloadContext *h263_new_context(void)
|
|
{
|
|
return av_mallocz(sizeof(PayloadContext));
|
|
}
|
|
|
|
static void h263_free_context(PayloadContext *data)
|
|
{
|
|
if (!data)
|
|
return;
|
|
if (data->buf) {
|
|
uint8_t *p;
|
|
avio_close_dyn_buf(data->buf, &p);
|
|
av_free(p);
|
|
}
|
|
av_free(data);
|
|
}
|
|
|
|
static av_cold int h263_init(AVFormatContext *ctx, int st_index, PayloadContext *data)
|
|
{
|
|
if (st_index < 0)
|
|
return 0;
|
|
ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
|
|
return 0;
|
|
}
|
|
|
|
static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data,
|
|
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
|
|
const uint8_t *buf, int len, uint16_t seq,
|
|
int flags)
|
|
{
|
|
/* Corresponding to header fields in the RFC */
|
|
int f, p, i, sbit, ebit, src, r;
|
|
int header_size, ret;
|
|
|
|
if (data->newformat)
|
|
return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf, len,
|
|
seq, flags);
|
|
|
|
if (data->buf && data->timestamp != *timestamp) {
|
|
/* Dropping old buffered, unfinished data */
|
|
uint8_t *p;
|
|
avio_close_dyn_buf(data->buf, &p);
|
|
av_free(p);
|
|
data->buf = NULL;
|
|
}
|
|
|
|
if (len < 4) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short H.263 RTP packet: %d\n", len);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
f = buf[0] & 0x80;
|
|
p = buf[0] & 0x40;
|
|
if (!f) {
|
|
/* Mode A */
|
|
header_size = 4;
|
|
i = buf[1] & 0x10;
|
|
r = ((buf[1] & 0x01) << 3) | ((buf[2] & 0xe0) >> 5);
|
|
} else if (!p) {
|
|
/* Mode B */
|
|
header_size = 8;
|
|
if (len < header_size) {
|
|
av_log(ctx, AV_LOG_ERROR,
|
|
"Too short H.263 RTP packet: %d bytes, %d header bytes\n",
|
|
len, header_size);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
r = buf[3] & 0x03;
|
|
i = buf[4] & 0x80;
|
|
} else {
|
|
/* Mode C */
|
|
header_size = 12;
|
|
if (len < header_size) {
|
|
av_log(ctx, AV_LOG_ERROR,
|
|
"Too short H.263 RTP packet: %d bytes, %d header bytes\n",
|
|
len, header_size);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
r = buf[3] & 0x03;
|
|
i = buf[4] & 0x80;
|
|
}
|
|
sbit = (buf[0] >> 3) & 0x7;
|
|
ebit = buf[0] & 0x7;
|
|
src = (buf[1] & 0xe0) >> 5;
|
|
if (!(buf[0] & 0xf8)) { /* Reserved bits in RFC 2429/4629 are zero */
|
|
if ((src == 0 || src >= 6) && r) {
|
|
/* Invalid src for this format, and bits that should be zero
|
|
* according to RFC 2190 aren't zero. */
|
|
av_log(ctx, AV_LOG_WARNING,
|
|
"Interpreting H263 RTP data as RFC 2429/4629 even though "
|
|
"signalled with a static payload type.\n");
|
|
data->newformat = 1;
|
|
return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf,
|
|
len, seq, flags);
|
|
}
|
|
}
|
|
|
|
buf += header_size;
|
|
len -= header_size;
|
|
|
|
if (!data->buf) {
|
|
/* Check the picture start code, only start buffering a new frame
|
|
* if this is correct */
|
|
if (len > 4 && AV_RB32(buf) >> 10 == 0x20) {
|
|
ret = avio_open_dyn_buf(&data->buf);
|
|
if (ret < 0)
|
|
return ret;
|
|
data->timestamp = *timestamp;
|
|
} else {
|
|
/* Frame not started yet, skipping */
|
|
return AVERROR(EAGAIN);
|
|
}
|
|
}
|
|
|
|
if (data->endbyte_bits || sbit) {
|
|
if (data->endbyte_bits == sbit) {
|
|
data->endbyte |= buf[0] & (0xff >> sbit);
|
|
data->endbyte_bits = 0;
|
|
buf++;
|
|
len--;
|
|
avio_w8(data->buf, data->endbyte);
|
|
} else {
|
|
/* Start/end skip bits not matching - missed packets? */
|
|
GetBitContext gb;
|
|
init_get_bits(&gb, buf, len*8 - ebit);
|
|
skip_bits(&gb, sbit);
|
|
if (data->endbyte_bits) {
|
|
data->endbyte |= get_bits(&gb, 8 - data->endbyte_bits);
|
|
avio_w8(data->buf, data->endbyte);
|
|
}
|
|
while (get_bits_left(&gb) >= 8)
|
|
avio_w8(data->buf, get_bits(&gb, 8));
|
|
data->endbyte_bits = get_bits_left(&gb);
|
|
if (data->endbyte_bits)
|
|
data->endbyte = get_bits(&gb, data->endbyte_bits) <<
|
|
(8 - data->endbyte_bits);
|
|
ebit = 0;
|
|
len = 0;
|
|
}
|
|
}
|
|
if (ebit) {
|
|
if (len > 0)
|
|
avio_write(data->buf, buf, len - 1);
|
|
data->endbyte_bits = 8 - ebit;
|
|
data->endbyte = buf[len - 1] & (0xff << ebit);
|
|
} else {
|
|
avio_write(data->buf, buf, len);
|
|
}
|
|
|
|
if (!(flags & RTP_FLAG_MARKER))
|
|
return AVERROR(EAGAIN);
|
|
|
|
if (data->endbyte_bits)
|
|
avio_w8(data->buf, data->endbyte);
|
|
data->endbyte_bits = 0;
|
|
|
|
ret = ff_rtp_finalize_packet(pkt, &data->buf, st->index);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (!i)
|
|
pkt->flags |= AV_PKT_FLAG_KEY;
|
|
|
|
return 0;
|
|
}
|
|
|
|
RTPDynamicProtocolHandler ff_h263_rfc2190_dynamic_handler = {
|
|
.codec_type = AVMEDIA_TYPE_VIDEO,
|
|
.codec_id = AV_CODEC_ID_H263,
|
|
.init = h263_init,
|
|
.parse_packet = h263_handle_packet,
|
|
.alloc = h263_new_context,
|
|
.free = h263_free_context,
|
|
.static_payload_id = 34,
|
|
};
|