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/*
* Common code for the RTP depacketization of MPEG-4 formats.
* Copyright (c) 2010 Fabrice Bellard
* Romain Degez
*
* 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 MPEG4 / RTP Code
* @author Fabrice Bellard
* @author Romain Degez
*/
#include "rtpdec_formats.h"
#include "internal.h"
#include "libavutil/attributes.h"
#include "libavutil/avstring.h"
#include "libavcodec/get_bits.h"
/** Structure listing useful vars to parse RTP packet payload */
struct PayloadContext {
int sizelength;
int indexlength;
int indexdeltalength;
int profile_level_id;
int streamtype;
int objecttype;
char *mode;
/** mpeg 4 AU headers */
struct AUHeaders {
int size;
int index;
int cts_flag;
int cts;
int dts_flag;
int dts;
int rap_flag;
int streamstate;
} *au_headers;
int au_headers_allocated;
int nb_au_headers;
int au_headers_length_bytes;
int cur_au_index;
uint8_t buf[RTP_MAX_PACKET_LENGTH];
int buf_pos, buf_size;
};
typedef struct {
const char *str;
uint16_t type;
uint32_t offset;
} AttrNameMap;
/* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
#define ATTR_NAME_TYPE_INT 0
#define ATTR_NAME_TYPE_STR 1
static const AttrNameMap attr_names[] = {
{ "SizeLength", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, sizelength) },
{ "IndexLength", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, indexlength) },
{ "IndexDeltaLength", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, indexdeltalength) },
{ "profile-level-id", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, profile_level_id) },
{ "StreamType", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, streamtype) },
{ "mode", ATTR_NAME_TYPE_STR,
offsetof(PayloadContext, mode) },
{ NULL, -1, -1 },
};
static PayloadContext *new_context(void)
{
return av_mallocz(sizeof(PayloadContext));
}
static void free_context(PayloadContext *data)
{
av_free(data->au_headers);
av_free(data->mode);
av_free(data);
}
static int parse_fmtp_config(AVCodecContext *codec, char *value)
{
/* decode the hexa encoded parameter */
int len = ff_hex_to_data(NULL, value);
av_free(codec->extradata);
if (ff_alloc_extradata(codec, len))
return AVERROR(ENOMEM);
ff_hex_to_data(codec->extradata, value);
return 0;
}
static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
{
int au_headers_length, au_header_size, i;
GetBitContext getbitcontext;
if (len < 2)
return AVERROR_INVALIDDATA;
/* decode the first 2 bytes where the AUHeader sections are stored
length in bits */
au_headers_length = AV_RB16(buf);
if (au_headers_length > RTP_MAX_PACKET_LENGTH)
return -1;
data->au_headers_length_bytes = (au_headers_length + 7) / 8;
/* skip AU headers length section (2 bytes) */
buf += 2;
len -= 2;
if (len < data->au_headers_length_bytes)
return AVERROR_INVALIDDATA;
init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
/* XXX: Wrong if optional additional sections are present (cts, dts etc...) */
au_header_size = data->sizelength + data->indexlength;
if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
return -1;
data->nb_au_headers = au_headers_length / au_header_size;
if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
av_free(data->au_headers);
data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
if (!data->au_headers)
return AVERROR(ENOMEM);
data->au_headers_allocated = data->nb_au_headers;
}
for (i = 0; i < data->nb_au_headers; ++i) {
data->au_headers[i].size = get_bits_long(&getbitcontext, data->sizelength);
data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength);
}
return 0;
}
/* Follows RFC 3640 */
static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq,
int flags)
{
int ret;
if (!buf) {
if (data->cur_au_index > data->nb_au_headers)
return AVERROR_INVALIDDATA;
if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size)
return AVERROR_INVALIDDATA;
if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0)
return ret;
memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size);
data->buf_pos += data->au_headers[data->cur_au_index].size;
pkt->stream_index = st->index;
data->cur_au_index++;
return data->cur_au_index < data->nb_au_headers;
}
if (rtp_parse_mp4_au(data, buf, len))
return -1;
buf += data->au_headers_length_bytes + 2;
len -= data->au_headers_length_bytes + 2;
if (len < data->au_headers[0].size)
return AVERROR_INVALIDDATA;
if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0)
return ret;
memcpy(pkt->data, buf, data->au_headers[0].size);
len -= data->au_headers[0].size;
buf += data->au_headers[0].size;
pkt->stream_index = st->index;
if (len > 0 && data->nb_au_headers > 1) {
data->buf_size = FFMIN(len, sizeof(data->buf));
memcpy(data->buf, buf, data->buf_size);
data->cur_au_index = 1;
data->buf_pos = 0;
return 1;
}
return 0;
}
static int parse_fmtp(AVStream *stream, PayloadContext *data,
char *attr, char *value)
{
AVCodecContext *codec = stream->codec;
int res, i;
if (!strcmp(attr, "config")) {
res = parse_fmtp_config(codec, value);
if (res < 0)
return res;
}
if (codec->codec_id == AV_CODEC_ID_AAC) {
/* Looking for a known attribute */
for (i = 0; attr_names[i].str; ++i) {
if (!av_strcasecmp(attr, attr_names[i].str)) {
if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
*(int *)((char *)data+
attr_names[i].offset) = atoi(value);
} else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
*(char **)((char *)data+
attr_names[i].offset) = av_strdup(value);
}
}
}
return 0;
}
static int parse_sdp_line(AVFormatContext *s, int st_index,
PayloadContext *data, const char *line)
{
const char *p;
if (st_index < 0)
return 0;
if (av_strstart(line, "fmtp:", &p))
return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
return 0;
}
static av_cold int init_video(AVFormatContext *s, int st_index,
PayloadContext *data)
{
if (st_index < 0)
return 0;
s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
return 0;
}
RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
.enc_name = "MP4V-ES",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_MPEG4,
.init = init_video,
.parse_sdp_a_line = parse_sdp_line,
};
RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
.enc_name = "mpeg4-generic",
.codec_type = AVMEDIA_TYPE_AUDIO,
.codec_id = AV_CODEC_ID_AAC,
.parse_sdp_a_line = parse_sdp_line,
.alloc = new_context,
.free = free_context,
.parse_packet = aac_parse_packet
};
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