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ffmpeg/libavformat/rtpdec_h264.c

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/*
* RTP H264 Protocol (RFC3984)
* Copyright (c) 2006 Ryan Martell
*
* 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
*/
/**
* @file libavformat/rtpdec_h264.c
* @brief H.264 / RTP Code (RFC3984)
* @author Ryan Martell <rdm4@martellventures.com>
*
* @note Notes:
* Notes:
* This currently supports packetization mode:
* Single Nal Unit Mode (0), or
* Non-Interleaved Mode (1). It currently does not support
* Interleaved Mode (2). (This requires implementing STAP-B, MTAP16, MTAP24, FU-B packet types)
*
* @note TODO:
* 1) RTCP sender reports for udp streams are required..
*
*/
#include "libavutil/base64.h"
#include "libavutil/avstring.h"
#include "libavcodec/get_bits.h"
#include "avformat.h"
#include "mpegts.h"
#include <unistd.h>
#include "network.h"
#include <assert.h>
#include "rtpdec.h"
#include "rtpdec_h264.h"
/**
RTP/H264 specific private data.
*/
struct PayloadContext {
unsigned long cookie; ///< sanity check, to make sure we get the pointer we're expecting.
//sdp setup parameters
uint8_t profile_idc; ///< from the sdp setup parameters.
uint8_t profile_iop; ///< from the sdp setup parameters.
uint8_t level_idc; ///< from the sdp setup parameters.
int packetization_mode; ///< from the sdp setup parameters.
#ifdef DEBUG
int packet_types_received[32];
#endif
};
#define MAGIC_COOKIE (0xdeadbeef) ///< Cookie for the extradata; to verify we are what we think we are, and that we haven't been freed.
#define DEAD_COOKIE (0xdeaddead) ///< Cookie for the extradata; once it is freed.
/* ---------------- private code */
static void sdp_parse_fmtp_config_h264(AVStream * stream,
PayloadContext * h264_data,
char *attr, char *value)
{
AVCodecContext *codec = stream->codec;
assert(codec->codec_id == CODEC_ID_H264);
assert(h264_data != NULL);
if (!strcmp(attr, "packetization-mode")) {
av_log(codec, AV_LOG_DEBUG, "RTP Packetization Mode: %d\n", atoi(value));
h264_data->packetization_mode = atoi(value);
/*
Packetization Mode:
0 or not present: Single NAL mode (Only nals from 1-23 are allowed)
1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed.
2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A), and 29 (FU-B) are allowed.
*/
if (h264_data->packetization_mode > 1)
av_log(codec, AV_LOG_ERROR,
"Interleaved RTP mode is not supported yet.");
} else if (!strcmp(attr, "profile-level-id")) {
if (strlen(value) == 6) {
char buffer[3];
// 6 characters=3 bytes, in hex.
uint8_t profile_idc;
uint8_t profile_iop;
uint8_t level_idc;
buffer[0] = value[0]; buffer[1] = value[1]; buffer[2] = '\0';
profile_idc = strtol(buffer, NULL, 16);
buffer[0] = value[2]; buffer[1] = value[3];
profile_iop = strtol(buffer, NULL, 16);
buffer[0] = value[4]; buffer[1] = value[5];
level_idc = strtol(buffer, NULL, 16);
// set the parameters...
av_log(codec, AV_LOG_DEBUG,
"RTP Profile IDC: %x Profile IOP: %x Level: %x\n",
profile_idc, profile_iop, level_idc);
h264_data->profile_idc = profile_idc;
h264_data->profile_iop = profile_iop;
h264_data->level_idc = level_idc;
}
} else if (!strcmp(attr, "sprop-parameter-sets")) {
uint8_t start_sequence[]= { 0, 0, 1 };
codec->extradata_size= 0;
codec->extradata= NULL;
while (*value) {
char base64packet[1024];
uint8_t decoded_packet[1024];
uint32_t packet_size;
char *dst = base64packet;
while (*value && *value != ','
&& (dst - base64packet) < sizeof(base64packet) - 1) {
*dst++ = *value++;
}
*dst++ = '\0';
if (*value == ',')
value++;
packet_size= av_base64_decode(decoded_packet, base64packet, sizeof(decoded_packet));
if (packet_size) {
uint8_t *dest= av_malloc(packet_size+sizeof(start_sequence)+codec->extradata_size);
if(dest)
{
if(codec->extradata_size)
{
// av_realloc?
memcpy(dest, codec->extradata, codec->extradata_size);
av_free(codec->extradata);
}
memcpy(dest+codec->extradata_size, start_sequence, sizeof(start_sequence));
memcpy(dest+codec->extradata_size+sizeof(start_sequence), decoded_packet, packet_size);
codec->extradata= dest;
codec->extradata_size+= sizeof(start_sequence)+packet_size;
} else {
av_log(codec, AV_LOG_ERROR, "Unable to allocate memory for extradata!");
}
}
}
av_log(codec, AV_LOG_DEBUG, "Extradata set to %p (size: %d)!", codec->extradata, codec->extradata_size);
}
}
// return 0 on packet, no more left, 1 on packet, 1 on partial packet...
static int h264_handle_packet(AVFormatContext *ctx,
PayloadContext *data,
AVStream *st,
AVPacket * pkt,
uint32_t * timestamp,
const uint8_t * buf,
int len, int flags)
{
uint8_t nal = buf[0];
uint8_t type = (nal & 0x1f);
int result= 0;
uint8_t start_sequence[]= {0, 0, 1};
#ifdef DEBUG
assert(data);
assert(data->cookie == MAGIC_COOKIE);
#endif
assert(buf);
if (type >= 1 && type <= 23)
type = 1; // simplify the case. (these are all the nal types used internally by the h264 codec)
switch (type) {
case 0: // undefined;
result= -1;
break;
case 1:
av_new_packet(pkt, len+sizeof(start_sequence));
memcpy(pkt->data, start_sequence, sizeof(start_sequence));
memcpy(pkt->data+sizeof(start_sequence), buf, len);
#ifdef DEBUG
data->packet_types_received[nal & 0x1f]++;
#endif
break;
case 24: // STAP-A (one packet, multiple nals)
// consume the STAP-A NAL
buf++;
len--;
// first we are going to figure out the total size....
{
int pass= 0;
int total_length= 0;
uint8_t *dst= NULL;
for(pass= 0; pass<2; pass++) {
const uint8_t *src= buf;
int src_len= len;
do {
uint16_t nal_size = AV_RB16(src); // this going to be a problem if unaligned (can it be?)
// consume the length of the aggregate...
src += 2;
src_len -= 2;
if (nal_size <= src_len) {
if(pass==0) {
// counting...
total_length+= sizeof(start_sequence)+nal_size;
} else {
// copying
assert(dst);
memcpy(dst, start_sequence, sizeof(start_sequence));
dst+= sizeof(start_sequence);
memcpy(dst, src, nal_size);
#ifdef DEBUG
data->packet_types_received[*src & 0x1f]++;
#endif
dst+= nal_size;
}
} else {
av_log(ctx, AV_LOG_ERROR,
"nal size exceeds length: %d %d\n", nal_size, src_len);
}
// eat what we handled...
src += nal_size;
src_len -= nal_size;
if (src_len < 0)
av_log(ctx, AV_LOG_ERROR,
"Consumed more bytes than we got! (%d)\n", src_len);
} while (src_len > 2); // because there could be rtp padding..
if(pass==0) {
// now we know the total size of the packet (with the start sequences added)
av_new_packet(pkt, total_length);
dst= pkt->data;
} else {
assert(dst-pkt->data==total_length);
}
}
}
break;
case 25: // STAP-B
case 26: // MTAP-16
case 27: // MTAP-24
case 29: // FU-B
av_log(ctx, AV_LOG_ERROR,
"Unhandled type (%d) (See RFC for implementation details\n",
type);
result= -1;
break;
case 28: // FU-A (fragmented nal)
buf++;
len--; // skip the fu_indicator
{
// these are the same as above, we just redo them here for clarity...
uint8_t fu_indicator = nal;
uint8_t fu_header = *buf; // read the fu_header.
uint8_t start_bit = fu_header >> 7;
// uint8_t end_bit = (fu_header & 0x40) >> 6;
uint8_t nal_type = (fu_header & 0x1f);
uint8_t reconstructed_nal;
// reconstruct this packet's true nal; only the data follows..
reconstructed_nal = fu_indicator & (0xe0); // the original nal forbidden bit and NRI are stored in this packet's nal;
reconstructed_nal |= nal_type;
// skip the fu_header...
buf++;
len--;
#ifdef DEBUG
if (start_bit)
data->packet_types_received[nal_type]++;
#endif
if(start_bit) {
// copy in the start sequence, and the reconstructed nal....
av_new_packet(pkt, sizeof(start_sequence)+sizeof(nal)+len);
memcpy(pkt->data, start_sequence, sizeof(start_sequence));
pkt->data[sizeof(start_sequence)]= reconstructed_nal;
memcpy(pkt->data+sizeof(start_sequence)+sizeof(nal), buf, len);
} else {
av_new_packet(pkt, len);
memcpy(pkt->data, buf, len);
}
}
break;
case 30: // undefined
case 31: // undefined
default:
av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)", type);
result= -1;
break;
}
pkt->stream_index = st->index;
return result;
}
/* ---------------- public code */
static PayloadContext *h264_new_context(void)
{
PayloadContext *data =
av_mallocz(sizeof(PayloadContext) +
FF_INPUT_BUFFER_PADDING_SIZE);
if (data) {
data->cookie = MAGIC_COOKIE;
}
return data;
}
static void h264_free_context(PayloadContext *data)
{
#ifdef DEBUG
int ii;
for (ii = 0; ii < 32; ii++) {
if (data->packet_types_received[ii])
av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n",
data->packet_types_received[ii], ii);
}
#endif
assert(data);
assert(data->cookie == MAGIC_COOKIE);
// avoid stale pointers (assert)
data->cookie = DEAD_COOKIE;
// and clear out this...
av_free(data);
}
static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
PayloadContext *h264_data, const char *line)
{
AVStream *stream = s->streams[st_index];
AVCodecContext *codec = stream->codec;
const char *p = line;
assert(h264_data->cookie == MAGIC_COOKIE);
if (av_strstart(p, "framesize:", &p)) {
char buf1[50];
char *dst = buf1;
// remove the protocol identifier..
while (*p && *p == ' ') p++; // strip spaces.
while (*p && *p != ' ') p++; // eat protocol identifier
while (*p && *p == ' ') p++; // strip trailing spaces.
while (*p && *p != '-' && (dst - buf1) < sizeof(buf1) - 1) {
*dst++ = *p++;
}
*dst = '\0';
// a='framesize:96 320-240'
// set our parameters..
codec->width = atoi(buf1);
codec->height = atoi(p + 1); // skip the -
codec->pix_fmt = PIX_FMT_YUV420P;
} else if (av_strstart(p, "fmtp:", &p)) {
char attr[256];
char value[4096];
// remove the protocol identifier..
while (*p && *p == ' ') p++; // strip spaces.
while (*p && *p != ' ') p++; // eat protocol identifier
while (*p && *p == ' ') p++; // strip trailing spaces.
/* loop on each attribute */
while (ff_rtsp_next_attr_and_value
(&p, attr, sizeof(attr), value, sizeof(value))) {
/* grab the codec extra_data from the config parameter of the fmtp line */
sdp_parse_fmtp_config_h264(stream, h264_data, attr, value);
}
} else if (av_strstart(p, "cliprect:", &p)) {
// could use this if we wanted.
}
av_set_pts_info(stream, 33, 1, 90000); // 33 should be right, because the pts is 64 bit? (done elsewhere; this is a one time thing)
return 0; // keep processing it the normal way...
}
/**
This is the structure for expanding on the dynamic rtp protocols (makes everything static. yay!)
*/
RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
.enc_name = "H264",
.codec_type = CODEC_TYPE_VIDEO,
.codec_id = CODEC_ID_H264,
.parse_sdp_a_line = parse_h264_sdp_line,
.open = h264_new_context,
.close = h264_free_context,
.parse_packet = h264_handle_packet
};
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