yading@11: /*
yading@11:  * Common code for the RTP depacketization of MPEG-4 formats.
yading@11:  * Copyright (c) 2010 Fabrice Bellard
yading@11:  *                    Romain Degez
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * @brief MPEG4 / RTP Code
yading@11:  * @author Fabrice Bellard
yading@11:  * @author Romain Degez
yading@11:  */
yading@11: 
yading@11: #include "rtpdec_formats.h"
yading@11: #include "internal.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavcodec/get_bits.h"
yading@11: 
yading@11: /** Structure listing useful vars to parse RTP packet payload */
yading@11: struct PayloadContext {
yading@11:     int sizelength;
yading@11:     int indexlength;
yading@11:     int indexdeltalength;
yading@11:     int profile_level_id;
yading@11:     int streamtype;
yading@11:     int objecttype;
yading@11:     char *mode;
yading@11: 
yading@11:     /** mpeg 4 AU headers */
yading@11:     struct AUHeaders {
yading@11:         int size;
yading@11:         int index;
yading@11:         int cts_flag;
yading@11:         int cts;
yading@11:         int dts_flag;
yading@11:         int dts;
yading@11:         int rap_flag;
yading@11:         int streamstate;
yading@11:     } *au_headers;
yading@11:     int au_headers_allocated;
yading@11:     int nb_au_headers;
yading@11:     int au_headers_length_bytes;
yading@11:     int cur_au_index;
yading@11: 
yading@11:     uint8_t buf[RTP_MAX_PACKET_LENGTH];
yading@11:     int buf_pos, buf_size;
yading@11: };
yading@11: 
yading@11: typedef struct {
yading@11:     const char *str;
yading@11:     uint16_t    type;
yading@11:     uint32_t    offset;
yading@11: } AttrNameMap;
yading@11: 
yading@11: /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
yading@11: #define ATTR_NAME_TYPE_INT 0
yading@11: #define ATTR_NAME_TYPE_STR 1
yading@11: static const AttrNameMap attr_names[] = {
yading@11:     { "SizeLength",       ATTR_NAME_TYPE_INT,
yading@11:       offsetof(PayloadContext, sizelength) },
yading@11:     { "IndexLength",      ATTR_NAME_TYPE_INT,
yading@11:       offsetof(PayloadContext, indexlength) },
yading@11:     { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
yading@11:       offsetof(PayloadContext, indexdeltalength) },
yading@11:     { "profile-level-id", ATTR_NAME_TYPE_INT,
yading@11:       offsetof(PayloadContext, profile_level_id) },
yading@11:     { "StreamType",       ATTR_NAME_TYPE_INT,
yading@11:       offsetof(PayloadContext, streamtype) },
yading@11:     { "mode",             ATTR_NAME_TYPE_STR,
yading@11:       offsetof(PayloadContext, mode) },
yading@11:     { NULL, -1, -1 },
yading@11: };
yading@11: 
yading@11: static PayloadContext *new_context(void)
yading@11: {
yading@11:     return av_mallocz(sizeof(PayloadContext));
yading@11: }
yading@11: 
yading@11: static void free_context(PayloadContext *data)
yading@11: {
yading@11:     av_free(data->au_headers);
yading@11:     av_free(data->mode);
yading@11:     av_free(data);
yading@11: }
yading@11: 
yading@11: static int parse_fmtp_config(AVCodecContext *codec, char *value)
yading@11: {
yading@11:     /* decode the hexa encoded parameter */
yading@11:     int len = ff_hex_to_data(NULL, value);
yading@11:     av_free(codec->extradata);
yading@11:     codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     if (!codec->extradata)
yading@11:         return AVERROR(ENOMEM);
yading@11:     codec->extradata_size = len;
yading@11:     ff_hex_to_data(codec->extradata, value);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
yading@11: {
yading@11:     int au_headers_length, au_header_size, i;
yading@11:     GetBitContext getbitcontext;
yading@11: 
yading@11:     if (len < 2)
yading@11:         return AVERROR_INVALIDDATA;
yading@11: 
yading@11:     /* decode the first 2 bytes where the AUHeader sections are stored
yading@11:        length in bits */
yading@11:     au_headers_length = AV_RB16(buf);
yading@11: 
yading@11:     if (au_headers_length > RTP_MAX_PACKET_LENGTH)
yading@11:       return -1;
yading@11: 
yading@11:     data->au_headers_length_bytes = (au_headers_length + 7) / 8;
yading@11: 
yading@11:     /* skip AU headers length section (2 bytes) */
yading@11:     buf += 2;
yading@11:     len -= 2;
yading@11: 
yading@11:     if (len < data->au_headers_length_bytes)
yading@11:         return AVERROR_INVALIDDATA;
yading@11: 
yading@11:     init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
yading@11: 
yading@11:     /* XXX: Wrong if optional additional sections are present (cts, dts etc...) */
yading@11:     au_header_size = data->sizelength + data->indexlength;
yading@11:     if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
yading@11:         return -1;
yading@11: 
yading@11:     data->nb_au_headers = au_headers_length / au_header_size;
yading@11:     if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
yading@11:         av_free(data->au_headers);
yading@11:         data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
yading@11:         if (!data->au_headers)
yading@11:             return AVERROR(ENOMEM);
yading@11:         data->au_headers_allocated = data->nb_au_headers;
yading@11:     }
yading@11: 
yading@11:     for (i = 0; i < data->nb_au_headers; ++i) {
yading@11:         data->au_headers[i].size  = get_bits_long(&getbitcontext, data->sizelength);
yading@11:         data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength);
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: 
yading@11: /* Follows RFC 3640 */
yading@11: static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
yading@11:                             AVStream *st, AVPacket *pkt, uint32_t *timestamp,
yading@11:                             const uint8_t *buf, int len, uint16_t seq,
yading@11:                             int flags)
yading@11: {
yading@11:     int ret;
yading@11: 
yading@11:     if (!buf) {
yading@11:         if (data->cur_au_index > data->nb_au_headers)
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size)
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0)
yading@11:             return ret;
yading@11:         memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size);
yading@11:         data->buf_pos += data->au_headers[data->cur_au_index].size;
yading@11:         pkt->stream_index = st->index;
yading@11:         data->cur_au_index++;
yading@11:         return data->cur_au_index < data->nb_au_headers;
yading@11:     }
yading@11: 
yading@11:     if (rtp_parse_mp4_au(data, buf, len))
yading@11:         return -1;
yading@11: 
yading@11:     buf += data->au_headers_length_bytes + 2;
yading@11:     len -= data->au_headers_length_bytes + 2;
yading@11: 
yading@11:     if (len < data->au_headers[0].size)
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0)
yading@11:         return ret;
yading@11:     memcpy(pkt->data, buf, data->au_headers[0].size);
yading@11:     len -= data->au_headers[0].size;
yading@11:     buf += data->au_headers[0].size;
yading@11:     pkt->stream_index = st->index;
yading@11: 
yading@11:     if (len > 0 && data->nb_au_headers > 1) {
yading@11:         data->buf_size = FFMIN(len, sizeof(data->buf));
yading@11:         memcpy(data->buf, buf, data->buf_size);
yading@11:         data->cur_au_index = 1;
yading@11:         data->buf_pos = 0;
yading@11:         return 1;
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int parse_fmtp(AVStream *stream, PayloadContext *data,
yading@11:                       char *attr, char *value)
yading@11: {
yading@11:     AVCodecContext *codec = stream->codec;
yading@11:     int res, i;
yading@11: 
yading@11:     if (!strcmp(attr, "config")) {
yading@11:         res = parse_fmtp_config(codec, value);
yading@11: 
yading@11:         if (res < 0)
yading@11:             return res;
yading@11:     }
yading@11: 
yading@11:     if (codec->codec_id == AV_CODEC_ID_AAC) {
yading@11:         /* Looking for a known attribute */
yading@11:         for (i = 0; attr_names[i].str; ++i) {
yading@11:             if (!av_strcasecmp(attr, attr_names[i].str)) {
yading@11:                 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
yading@11:                     *(int *)((char *)data+
yading@11:                         attr_names[i].offset) = atoi(value);
yading@11:                 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
yading@11:                     *(char **)((char *)data+
yading@11:                         attr_names[i].offset) = av_strdup(value);
yading@11:             }
yading@11:         }
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int parse_sdp_line(AVFormatContext *s, int st_index,
yading@11:                           PayloadContext *data, const char *line)
yading@11: {
yading@11:     const char *p;
yading@11: 
yading@11:     if (st_index < 0)
yading@11:         return 0;
yading@11: 
yading@11:     if (av_strstart(line, "fmtp:", &p))
yading@11:         return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int init_video(AVFormatContext *s, int st_index, PayloadContext *data)
yading@11: {
yading@11:     if (st_index < 0)
yading@11:         return 0;
yading@11:     s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
yading@11:     .enc_name           = "MP4V-ES",
yading@11:     .codec_type         = AVMEDIA_TYPE_VIDEO,
yading@11:     .codec_id           = AV_CODEC_ID_MPEG4,
yading@11:     .init               = init_video,
yading@11:     .parse_sdp_a_line   = parse_sdp_line,
yading@11: };
yading@11: 
yading@11: RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
yading@11:     .enc_name           = "mpeg4-generic",
yading@11:     .codec_type         = AVMEDIA_TYPE_AUDIO,
yading@11:     .codec_id           = AV_CODEC_ID_AAC,
yading@11:     .parse_sdp_a_line   = parse_sdp_line,
yading@11:     .alloc              = new_context,
yading@11:     .free               = free_context,
yading@11:     .parse_packet       = aac_parse_packet
yading@11: };