| /** |
| * 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/avstring.h" |
| #include "libavcodec/get_bits.h" |
| #include <strings.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; |
| }; |
| |
| 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) |
| { |
| int i; |
| for (i = 0; i < data->nb_au_headers; i++) { |
| /* according to rtp_parse_mp4_au, we treat multiple |
| * au headers as one, so nb_au_headers is always 1. |
| * loop anyway in case this changes. |
| * (note: changes done carelessly might lead to a double free) |
| */ |
| av_free(&data->au_headers[i]); |
| } |
| 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); |
| codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE); |
| if (!codec->extradata) |
| return AVERROR(ENOMEM); |
| codec->extradata_size = len; |
| ff_hex_to_data(codec->extradata, value); |
| return 0; |
| } |
| |
| static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf) |
| { |
| int au_headers_length, au_header_size, i; |
| GetBitContext getbitcontext; |
| |
| /* 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; |
| |
| 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); |
| data->au_headers_allocated = data->nb_au_headers; |
| } |
| |
| /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving) |
| In my test, the FAAD decoder does not behave correctly when sending each AU one by one |
| but does when sending the whole as one big packet... */ |
| data->au_headers[0].size = 0; |
| data->au_headers[0].index = 0; |
| for (i = 0; i < data->nb_au_headers; ++i) { |
| data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength); |
| data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength); |
| } |
| |
| data->nb_au_headers = 1; |
| |
| 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, int flags) |
| { |
| if (rtp_parse_mp4_au(data, buf)) |
| return -1; |
| |
| buf += data->au_headers_length_bytes + 2; |
| len -= data->au_headers_length_bytes + 2; |
| |
| /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define |
| one au_header */ |
| av_new_packet(pkt, data->au_headers[0].size); |
| memcpy(pkt->data, buf, data->au_headers[0].size); |
| |
| pkt->stream_index = st->index; |
| 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 == CODEC_ID_AAC) { |
| /* Looking for a known attribute */ |
| for (i = 0; attr_names[i].str; ++i) { |
| if (!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 (av_strstart(line, "fmtp:", &p)) |
| return ff_parse_fmtp(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 = CODEC_ID_MPEG4, |
| .parse_sdp_a_line = parse_sdp_line, |
| .alloc = NULL, |
| .free = NULL, |
| .parse_packet = NULL |
| }; |
| |
| RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = { |
| .enc_name = "mpeg4-generic", |
| .codec_type = AVMEDIA_TYPE_AUDIO, |
| .codec_id = CODEC_ID_AAC, |
| .parse_sdp_a_line = parse_sdp_line, |
| .alloc = new_context, |
| .free = free_context, |
| .parse_packet = aac_parse_packet |
| }; |