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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 Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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"
#define MAX_AAC_HBR_FRAME_SIZE 8191
/** 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[FFMAX(RTP_MAX_PACKET_LENGTH, MAX_AAC_HBR_FRAME_SIZE)];
int buf_pos, buf_size;
uint32_t timestamp;
};
typedef struct AttrNameMap {
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 void close_context(PayloadContext *data)
{
av_free(data->au_headers);
av_free(data->mode);
}
static int parse_fmtp_config(AVCodecParameters *par, char *value)
{
/* decode the hexa encoded parameter */
int len = ff_hex_to_data(NULL, value);
av_free(par->extradata);
par->extradata = av_mallocz(len + AV_INPUT_BUFFER_PADDING_SIZE);
if (!par->extradata)
return AVERROR(ENOMEM);
par->extradata_size = len;
ff_hex_to_data(par->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 optionnal 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) {
av_log(ctx, AV_LOG_ERROR, "Invalid parser state\n");
return AVERROR_INVALIDDATA;
}
if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size) {
av_log(ctx, AV_LOG_ERROR, "Invalid AU size\n");
return AVERROR_INVALIDDATA;
}
if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
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++;
if (data->cur_au_index == data->nb_au_headers) {
data->buf_pos = 0;
return 0;
}
return 1;
}
if (rtp_parse_mp4_au(data, buf, len)) {
av_log(ctx, AV_LOG_ERROR, "Error parsing AU headers\n");
return -1;
}
buf += data->au_headers_length_bytes + 2;
len -= data->au_headers_length_bytes + 2;
if (data->nb_au_headers == 1 && len < data->au_headers[0].size) {
/* Packet is fragmented */
if (!data->buf_pos) {
if (data->au_headers[0].size > MAX_AAC_HBR_FRAME_SIZE) {
av_log(ctx, AV_LOG_ERROR, "Invalid AU size\n");
return AVERROR_INVALIDDATA;
}
data->buf_size = data->au_headers[0].size;
data->timestamp = *timestamp;
}
if (data->timestamp != *timestamp ||
data->au_headers[0].size != data->buf_size ||
data->buf_pos + len > MAX_AAC_HBR_FRAME_SIZE) {
data->buf_pos = 0;
data->buf_size = 0;
av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
return AVERROR_INVALIDDATA;
}
memcpy(&data->buf[data->buf_pos], buf, len);
data->buf_pos += len;
if (!(flags & RTP_FLAG_MARKER))
return AVERROR(EAGAIN);
if (data->buf_pos != data->buf_size) {
data->buf_pos = 0;
av_log(ctx, AV_LOG_ERROR, "Missed some packets, discarding frame\n");
return AVERROR_INVALIDDATA;
}
data->buf_pos = 0;
ret = av_new_packet(pkt, data->buf_size);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
return ret;
}
pkt->stream_index = st->index;
memcpy(pkt->data, data->buf, data->buf_size);
return 0;
}
if (len < data->au_headers[0].size) {
av_log(ctx, AV_LOG_ERROR, "First AU larger than packet size\n");
return AVERROR_INVALIDDATA;
}
if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
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(AVFormatContext *s,
AVStream *stream, PayloadContext *data,
const char *attr, const char *value)
{
AVCodecParameters *par = stream->codecpar;
int res, i;
if (!strcmp(attr, "config")) {
res = parse_fmtp_config(par, value);
if (res < 0)
return res;
}
if (par->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, s->streams[st_index], data, p, parse_fmtp);
return 0;
}
RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
.enc_name = "MP4V-ES",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_MPEG4,
.need_parsing = AVSTREAM_PARSE_FULL,
.priv_data_size = sizeof(PayloadContext),
.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,
.priv_data_size = sizeof(PayloadContext),
.parse_sdp_a_line = parse_sdp_line,
.close = close_context,
.parse_packet = aac_parse_packet,
};
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