summaryrefslogtreecommitdiff
path: root/libavformat/rtpdec_mpeg4.c
blob: 994ab49251769f8bdddbb9246237f1d18a10483c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
/*
 * 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 MPEG-4 / 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_freep(&data->au_headers);
    av_freep(&data->mode);
}

static int parse_fmtp_config(AVCodecParameters *par, const char *value)
{
    /* decode the hexa encoded parameter */
    int len = ff_hex_to_data(NULL, value);
    av_freep(&par->extradata);
    if (ff_alloc_extradata(par, len))
        return AVERROR(ENOMEM);
    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 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) {
            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 val = atoi(value);
                    if (val > 32) {
                        av_log(s, AV_LOG_ERROR,
                               "The %s field size is invalid (%d)\n",
                               attr, val);
                        return AVERROR_INVALIDDATA;
                    }
                    *(int *)((char *)data+
                        attr_names[i].offset) = val;
                } else if (attr_names[i].type == ATTR_NAME_TYPE_STR) {
                    char *val = av_strdup(value);
                    if (!val)
                        return AVERROR(ENOMEM);
                    *(char **)((char *)data+
                        attr_names[i].offset) = val;
                }
            }
        }
    }
    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,
};