diff options
Diffstat (limited to 'ffmpeg/libavformat/rtpdec_mpeg4.c')
| -rw-r--r-- | ffmpeg/libavformat/rtpdec_mpeg4.c | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/ffmpeg/libavformat/rtpdec_mpeg4.c b/ffmpeg/libavformat/rtpdec_mpeg4.c new file mode 100644 index 0000000..3f1f244 --- /dev/null +++ b/ffmpeg/libavformat/rtpdec_mpeg4.c @@ -0,0 +1,279 @@ +/* + * 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" + +/** 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); + 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 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 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 +}; |