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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
* @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)
*/
#include "libavutil/attributes.h"
#include "libavutil/base64.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/avstring.h"
#include "avformat.h"
#include "rtpdec.h"
#include "rtpdec_formats.h"
struct PayloadContext {
// sdp setup parameters
uint8_t profile_idc;
uint8_t profile_iop;
uint8_t level_idc;
int packetization_mode;
#ifdef DEBUG
int packet_types_received[32];
#endif
};
#ifdef DEBUG
#define COUNT_NAL_TYPE(data, nal) data->packet_types_received[(nal) & 0x1f]++
#define NAL_COUNTERS data->packet_types_received
#else
#define COUNT_NAL_TYPE(data, nal) do { } while (0)
#define NAL_COUNTERS NULL
#endif
#define NAL_MASK 0x1f
static const uint8_t start_sequence[] = { 0, 0, 0, 1 };
static void parse_profile_level_id(AVFormatContext *s,
PayloadContext *h264_data,
const char *value)
{
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);
av_log(s, 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;
}
int ff_h264_parse_sprop_parameter_sets(AVFormatContext *s,
uint8_t **data_ptr, int *size_ptr,
const char *value)
{
char base64packet[1024];
uint8_t decoded_packet[1024];
int packet_size;
while (*value) {
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 > 0) {
uint8_t *dest = av_realloc(*data_ptr,
packet_size + sizeof(start_sequence) +
*size_ptr +
FF_INPUT_BUFFER_PADDING_SIZE);
if (!dest) {
av_log(s, AV_LOG_ERROR,
"Unable to allocate memory for extradata!\n");
return AVERROR(ENOMEM);
}
*data_ptr = dest;
memcpy(dest + *size_ptr, start_sequence,
sizeof(start_sequence));
memcpy(dest + *size_ptr + sizeof(start_sequence),
decoded_packet, packet_size);
memset(dest + *size_ptr + sizeof(start_sequence) +
packet_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
*size_ptr += sizeof(start_sequence) + packet_size;
}
}
return 0;
}
static int sdp_parse_fmtp_config_h264(AVFormatContext *s,
AVStream *stream,
PayloadContext *h264_data,
const char *attr, const char *value)
{
AVCodecContext *codec = stream->codec;
if (!strcmp(attr, "packetization-mode")) {
av_log(s, 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(s, AV_LOG_ERROR,
"Interleaved RTP mode is not supported yet.\n");
} else if (!strcmp(attr, "profile-level-id")) {
if (strlen(value) == 6)
parse_profile_level_id(s, h264_data, value);
} else if (!strcmp(attr, "sprop-parameter-sets")) {
int ret;
codec->extradata_size = 0;
av_freep(&codec->extradata);
ret = ff_h264_parse_sprop_parameter_sets(s, &codec->extradata,
&codec->extradata_size, value);
av_log(s, AV_LOG_DEBUG, "Extradata set to %p (size: %d)\n",
codec->extradata, codec->extradata_size);
return ret;
}
return 0;
}
void ff_h264_parse_framesize(AVCodecContext *codec, const char *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 -
}
int ff_h264_handle_aggregated_packet(AVFormatContext *ctx, PayloadContext *data, AVPacket *pkt,
const uint8_t *buf, int len,
int skip_between, int *nal_counters,
int nal_mask)
{
int pass = 0;
int total_length = 0;
uint8_t *dst = NULL;
int ret;
// first we are going to figure out the total size
for (pass = 0; pass < 2; pass++) {
const uint8_t *src = buf;
int src_len = len;
while (src_len > 2) {
uint16_t nal_size = AV_RB16(src);
// 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
memcpy(dst, start_sequence, sizeof(start_sequence));
dst += sizeof(start_sequence);
memcpy(dst, src, nal_size);
if (nal_counters)
nal_counters[(*src) & nal_mask]++;
dst += nal_size;
}
} else {
av_log(ctx, AV_LOG_ERROR,
"nal size exceeds length: %d %d\n", nal_size, src_len);
return AVERROR_INVALIDDATA;
}
// eat what we handled
src += nal_size + skip_between;
src_len -= nal_size + skip_between;
}
if (pass == 0) {
/* now we know the total size of the packet (with the
* start sequences added) */
if ((ret = av_new_packet(pkt, total_length)) < 0)
return ret;
dst = pkt->data;
}
}
return 0;
}
int ff_h264_handle_frag_packet(AVPacket *pkt, const uint8_t *buf, int len,
int start_bit, const uint8_t *nal_header,
int nal_header_len)
{
int ret;
int tot_len = len;
int pos = 0;
if (start_bit)
tot_len += sizeof(start_sequence) + nal_header_len;
if ((ret = av_new_packet(pkt, tot_len)) < 0)
return ret;
if (start_bit) {
memcpy(pkt->data + pos, start_sequence, sizeof(start_sequence));
pos += sizeof(start_sequence);
memcpy(pkt->data + pos, nal_header, nal_header_len);
pos += nal_header_len;
}
memcpy(pkt->data + pos, buf, len);
return 0;
}
static int h264_handle_packet_fu_a(AVFormatContext *ctx, PayloadContext *data, AVPacket *pkt,
const uint8_t *buf, int len,
int *nal_counters, int nal_mask)
{
uint8_t fu_indicator, fu_header, start_bit, nal_type, nal;
if (len < 3) {
av_log(ctx, AV_LOG_ERROR, "Too short data for FU-A H264 RTP packet\n");
return AVERROR_INVALIDDATA;
}
fu_indicator = buf[0];
fu_header = buf[1];
start_bit = fu_header >> 7;
nal_type = fu_header & 0x1f;
nal = fu_indicator & 0xe0 | nal_type;
// skip the fu_indicator and fu_header
buf += 2;
len -= 2;
if (start_bit && nal_counters)
nal_counters[nal_type & nal_mask]++;
return ff_h264_handle_frag_packet(pkt, buf, len, start_bit, &nal, 1);
}
// 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, uint16_t seq,
int flags)
{
uint8_t nal;
uint8_t type;
int result = 0;
if (!len) {
av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n");
return AVERROR_INVALIDDATA;
}
nal = buf[0];
type = nal & 0x1f;
/* Simplify the case (these are all the nal types used internally by
* the h264 codec). */
if (type >= 1 && type <= 23)
type = 1;
switch (type) {
case 0: // undefined, but pass them through
case 1:
if ((result = av_new_packet(pkt, len + sizeof(start_sequence))) < 0)
return result;
memcpy(pkt->data, start_sequence, sizeof(start_sequence));
memcpy(pkt->data + sizeof(start_sequence), buf, len);
COUNT_NAL_TYPE(data, nal);
break;
case 24: // STAP-A (one packet, multiple nals)
// consume the STAP-A NAL
buf++;
len--;
result = ff_h264_handle_aggregated_packet(ctx, data, pkt, buf, len, 0,
NAL_COUNTERS, NAL_MASK);
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 = AVERROR(ENOSYS);
break;
case 28: // FU-A (fragmented nal)
result = h264_handle_packet_fu_a(ctx, data, pkt, buf, len,
NAL_COUNTERS, NAL_MASK);
break;
case 30: // undefined
case 31: // undefined
default:
av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)\n", type);
result = AVERROR_INVALIDDATA;
break;
}
pkt->stream_index = st->index;
return result;
}
static void h264_close_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
}
static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
PayloadContext *h264_data, const char *line)
{
AVStream *stream;
const char *p = line;
if (st_index < 0)
return 0;
stream = s->streams[st_index];
if (av_strstart(p, "framesize:", &p)) {
ff_h264_parse_framesize(stream->codec, p);
} else if (av_strstart(p, "fmtp:", &p)) {
return ff_parse_fmtp(s, stream, h264_data, p, sdp_parse_fmtp_config_h264);
} else if (av_strstart(p, "cliprect:", &p)) {
// could use this if we wanted.
}
return 0;
}
RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
.enc_name = "H264",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_H264,
.need_parsing = AVSTREAM_PARSE_FULL,
.priv_data_size = sizeof(PayloadContext),
.parse_sdp_a_line = parse_h264_sdp_line,
.close = h264_close_context,
.parse_packet = h264_handle_packet,
};
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