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/libavformat/rtpdec_h264.c

http://github.com/FFmpeg/FFmpeg
C | 420 lines | 309 code | 53 blank | 58 comment | 65 complexity | 3b080465a3e7316a0215679767a14f0c MD5 | raw file
  1/*
  2 * RTP H.264 Protocol (RFC3984)
  3 * Copyright (c) 2006 Ryan Martell
  4 *
  5 * This file is part of FFmpeg.
  6 *
  7 * FFmpeg is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU Lesser General Public
  9 * License as published by the Free Software Foundation; either
 10 * version 2.1 of the License, or (at your option) any later version.
 11 *
 12 * FFmpeg is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 15 * Lesser General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU Lesser General Public
 18 * License along with FFmpeg; if not, write to the Free Software
 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 20 */
 21
 22/**
 23 * @file
 24 * @brief H.264 / RTP Code (RFC3984)
 25 * @author Ryan Martell <rdm4@martellventures.com>
 26 *
 27 * @note Notes:
 28 * Notes:
 29 * This currently supports packetization mode:
 30 * Single Nal Unit Mode (0), or
 31 * Non-Interleaved Mode (1).  It currently does not support
 32 * Interleaved Mode (2). (This requires implementing STAP-B, MTAP16, MTAP24,
 33 *                        FU-B packet types)
 34 */
 35
 36#include "libavutil/attributes.h"
 37#include "libavutil/base64.h"
 38#include "libavutil/intreadwrite.h"
 39#include "libavutil/avstring.h"
 40#include "avformat.h"
 41
 42#include "rtpdec.h"
 43#include "rtpdec_formats.h"
 44
 45struct PayloadContext {
 46    // sdp setup parameters
 47    uint8_t profile_idc;
 48    uint8_t profile_iop;
 49    uint8_t level_idc;
 50    int packetization_mode;
 51#ifdef DEBUG
 52    int packet_types_received[32];
 53#endif
 54};
 55
 56#ifdef DEBUG
 57#define COUNT_NAL_TYPE(data, nal) data->packet_types_received[(nal) & 0x1f]++
 58#define NAL_COUNTERS data->packet_types_received
 59#else
 60#define COUNT_NAL_TYPE(data, nal) do { } while (0)
 61#define NAL_COUNTERS NULL
 62#endif
 63#define NAL_MASK 0x1f
 64
 65static const uint8_t start_sequence[] = { 0, 0, 0, 1 };
 66
 67static void parse_profile_level_id(AVFormatContext *s,
 68                                   PayloadContext *h264_data,
 69                                   const char *value)
 70{
 71    char buffer[3];
 72    // 6 characters=3 bytes, in hex.
 73    uint8_t profile_idc;
 74    uint8_t profile_iop;
 75    uint8_t level_idc;
 76
 77    buffer[0]   = value[0];
 78    buffer[1]   = value[1];
 79    buffer[2]   = '\0';
 80    profile_idc = strtol(buffer, NULL, 16);
 81    buffer[0]   = value[2];
 82    buffer[1]   = value[3];
 83    profile_iop = strtol(buffer, NULL, 16);
 84    buffer[0]   = value[4];
 85    buffer[1]   = value[5];
 86    level_idc   = strtol(buffer, NULL, 16);
 87
 88    av_log(s, AV_LOG_DEBUG,
 89           "RTP Profile IDC: %x Profile IOP: %x Level: %x\n",
 90           profile_idc, profile_iop, level_idc);
 91    h264_data->profile_idc = profile_idc;
 92    h264_data->profile_iop = profile_iop;
 93    h264_data->level_idc   = level_idc;
 94}
 95
 96int ff_h264_parse_sprop_parameter_sets(AVFormatContext *s,
 97                                       uint8_t **data_ptr, int *size_ptr,
 98                                       const char *value)
 99{
100    char base64packet[1024];
101    uint8_t decoded_packet[1024];
102    int packet_size;
103
104    while (*value) {
105        char *dst = base64packet;
106
107        while (*value && *value != ','
108               && (dst - base64packet) < sizeof(base64packet) - 1) {
109            *dst++ = *value++;
110        }
111        *dst++ = '\0';
112
113        if (*value == ',')
114            value++;
115
116        packet_size = av_base64_decode(decoded_packet, base64packet,
117                                       sizeof(decoded_packet));
118        if (packet_size > 0) {
119            uint8_t *dest = av_realloc(*data_ptr,
120                                       packet_size + sizeof(start_sequence) +
121                                       *size_ptr +
122                                       AV_INPUT_BUFFER_PADDING_SIZE);
123            if (!dest) {
124                av_log(s, AV_LOG_ERROR,
125                       "Unable to allocate memory for extradata!\n");
126                return AVERROR(ENOMEM);
127            }
128            *data_ptr = dest;
129
130            memcpy(dest + *size_ptr, start_sequence,
131                   sizeof(start_sequence));
132            memcpy(dest + *size_ptr + sizeof(start_sequence),
133                   decoded_packet, packet_size);
134            memset(dest + *size_ptr + sizeof(start_sequence) +
135                   packet_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
136
137            *size_ptr += sizeof(start_sequence) + packet_size;
138        }
139    }
140
141    return 0;
142}
143
144static int sdp_parse_fmtp_config_h264(AVFormatContext *s,
145                                      AVStream *stream,
146                                      PayloadContext *h264_data,
147                                      const char *attr, const char *value)
148{
149    AVCodecParameters *par = stream->codecpar;
150
151    if (!strcmp(attr, "packetization-mode")) {
152        av_log(s, AV_LOG_DEBUG, "RTP Packetization Mode: %d\n", atoi(value));
153        h264_data->packetization_mode = atoi(value);
154        /*
155         * Packetization Mode:
156         * 0 or not present: Single NAL mode (Only nals from 1-23 are allowed)
157         * 1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed.
158         * 2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A),
159         *                      and 29 (FU-B) are allowed.
160         */
161        if (h264_data->packetization_mode > 1)
162            av_log(s, AV_LOG_ERROR,
163                   "Interleaved RTP mode is not supported yet.\n");
164    } else if (!strcmp(attr, "profile-level-id")) {
165        if (strlen(value) == 6)
166            parse_profile_level_id(s, h264_data, value);
167    } else if (!strcmp(attr, "sprop-parameter-sets")) {
168        int ret;
169        if (*value == 0 || value[strlen(value) - 1] == ',') {
170            av_log(s, AV_LOG_WARNING, "Missing PPS in sprop-parameter-sets, ignoring\n");
171            return 0;
172        }
173        par->extradata_size = 0;
174        av_freep(&par->extradata);
175        ret = ff_h264_parse_sprop_parameter_sets(s, &par->extradata,
176                                                 &par->extradata_size, value);
177        av_log(s, AV_LOG_DEBUG, "Extradata set to %p (size: %d)\n",
178               par->extradata, par->extradata_size);
179        return ret;
180    }
181    return 0;
182}
183
184void ff_h264_parse_framesize(AVCodecParameters *par, const char *p)
185{
186    char buf1[50];
187    char *dst = buf1;
188
189    // remove the protocol identifier
190    while (*p && *p == ' ')
191        p++;                     // strip spaces.
192    while (*p && *p != ' ')
193        p++;                     // eat protocol identifier
194    while (*p && *p == ' ')
195        p++;                     // strip trailing spaces.
196    while (*p && *p != '-' && (dst - buf1) < sizeof(buf1) - 1)
197        *dst++ = *p++;
198    *dst = '\0';
199
200    // a='framesize:96 320-240'
201    // set our parameters
202    par->width   = atoi(buf1);
203    par->height  = atoi(p + 1); // skip the -
204}
205
206int ff_h264_handle_aggregated_packet(AVFormatContext *ctx, PayloadContext *data, AVPacket *pkt,
207                                     const uint8_t *buf, int len,
208                                     int skip_between, int *nal_counters,
209                                     int nal_mask)
210{
211    int pass         = 0;
212    int total_length = 0;
213    uint8_t *dst     = NULL;
214    int ret;
215
216    // first we are going to figure out the total size
217    for (pass = 0; pass < 2; pass++) {
218        const uint8_t *src = buf;
219        int src_len        = len;
220
221        while (src_len > 2) {
222            uint16_t nal_size = AV_RB16(src);
223
224            // consume the length of the aggregate
225            src     += 2;
226            src_len -= 2;
227
228            if (nal_size <= src_len) {
229                if (pass == 0) {
230                    // counting
231                    total_length += sizeof(start_sequence) + nal_size;
232                } else {
233                    // copying
234                    memcpy(dst, start_sequence, sizeof(start_sequence));
235                    dst += sizeof(start_sequence);
236                    memcpy(dst, src, nal_size);
237                    if (nal_counters)
238                        nal_counters[(*src) & nal_mask]++;
239                    dst += nal_size;
240                }
241            } else {
242                av_log(ctx, AV_LOG_ERROR,
243                       "nal size exceeds length: %d %d\n", nal_size, src_len);
244                return AVERROR_INVALIDDATA;
245            }
246
247            // eat what we handled
248            src     += nal_size + skip_between;
249            src_len -= nal_size + skip_between;
250        }
251
252        if (pass == 0) {
253            /* now we know the total size of the packet (with the
254             * start sequences added) */
255            if ((ret = av_new_packet(pkt, total_length)) < 0)
256                return ret;
257            dst = pkt->data;
258        }
259    }
260
261    return 0;
262}
263
264int ff_h264_handle_frag_packet(AVPacket *pkt, const uint8_t *buf, int len,
265                               int start_bit, const uint8_t *nal_header,
266                               int nal_header_len)
267{
268    int ret;
269    int tot_len = len;
270    int pos = 0;
271    if (start_bit)
272        tot_len += sizeof(start_sequence) + nal_header_len;
273    if ((ret = av_new_packet(pkt, tot_len)) < 0)
274        return ret;
275    if (start_bit) {
276        memcpy(pkt->data + pos, start_sequence, sizeof(start_sequence));
277        pos += sizeof(start_sequence);
278        memcpy(pkt->data + pos, nal_header, nal_header_len);
279        pos += nal_header_len;
280    }
281    memcpy(pkt->data + pos, buf, len);
282    return 0;
283}
284
285static int h264_handle_packet_fu_a(AVFormatContext *ctx, PayloadContext *data, AVPacket *pkt,
286                                   const uint8_t *buf, int len,
287                                   int *nal_counters, int nal_mask)
288{
289    uint8_t fu_indicator, fu_header, start_bit, nal_type, nal;
290
291    if (len < 3) {
292        av_log(ctx, AV_LOG_ERROR, "Too short data for FU-A H.264 RTP packet\n");
293        return AVERROR_INVALIDDATA;
294    }
295
296    fu_indicator = buf[0];
297    fu_header    = buf[1];
298    start_bit    = fu_header >> 7;
299    nal_type     = fu_header & 0x1f;
300    nal          = fu_indicator & 0xe0 | nal_type;
301
302    // skip the fu_indicator and fu_header
303    buf += 2;
304    len -= 2;
305
306    if (start_bit && nal_counters)
307        nal_counters[nal_type & nal_mask]++;
308    return ff_h264_handle_frag_packet(pkt, buf, len, start_bit, &nal, 1);
309}
310
311// return 0 on packet, no more left, 1 on packet, 1 on partial packet
312static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data,
313                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
314                              const uint8_t *buf, int len, uint16_t seq,
315                              int flags)
316{
317    uint8_t nal;
318    uint8_t type;
319    int result = 0;
320
321    if (!len) {
322        av_log(ctx, AV_LOG_ERROR, "Empty H.264 RTP packet\n");
323        return AVERROR_INVALIDDATA;
324    }
325    nal  = buf[0];
326    type = nal & 0x1f;
327
328    /* Simplify the case (these are all the NAL types used internally by
329     * the H.264 codec). */
330    if (type >= 1 && type <= 23)
331        type = 1;
332    switch (type) {
333    case 0:                    // undefined, but pass them through
334    case 1:
335        if ((result = av_new_packet(pkt, len + sizeof(start_sequence))) < 0)
336            return result;
337        memcpy(pkt->data, start_sequence, sizeof(start_sequence));
338        memcpy(pkt->data + sizeof(start_sequence), buf, len);
339        COUNT_NAL_TYPE(data, nal);
340        break;
341
342    case 24:                   // STAP-A (one packet, multiple nals)
343        // consume the STAP-A NAL
344        buf++;
345        len--;
346        result = ff_h264_handle_aggregated_packet(ctx, data, pkt, buf, len, 0,
347                                                  NAL_COUNTERS, NAL_MASK);
348        break;
349
350    case 25:                   // STAP-B
351    case 26:                   // MTAP-16
352    case 27:                   // MTAP-24
353    case 29:                   // FU-B
354        avpriv_report_missing_feature(ctx, "RTP H.264 NAL unit type %d", type);
355        result = AVERROR_PATCHWELCOME;
356        break;
357
358    case 28:                   // FU-A (fragmented nal)
359        result = h264_handle_packet_fu_a(ctx, data, pkt, buf, len,
360                                         NAL_COUNTERS, NAL_MASK);
361        break;
362
363    case 30:                   // undefined
364    case 31:                   // undefined
365    default:
366        av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)\n", type);
367        result = AVERROR_INVALIDDATA;
368        break;
369    }
370
371    pkt->stream_index = st->index;
372
373    return result;
374}
375
376static void h264_close_context(PayloadContext *data)
377{
378#ifdef DEBUG
379    int ii;
380
381    for (ii = 0; ii < 32; ii++) {
382        if (data->packet_types_received[ii])
383            av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n",
384                   data->packet_types_received[ii], ii);
385    }
386#endif
387}
388
389static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
390                               PayloadContext *h264_data, const char *line)
391{
392    AVStream *stream;
393    const char *p = line;
394
395    if (st_index < 0)
396        return 0;
397
398    stream = s->streams[st_index];
399
400    if (av_strstart(p, "framesize:", &p)) {
401        ff_h264_parse_framesize(stream->codecpar, p);
402    } else if (av_strstart(p, "fmtp:", &p)) {
403        return ff_parse_fmtp(s, stream, h264_data, p, sdp_parse_fmtp_config_h264);
404    } else if (av_strstart(p, "cliprect:", &p)) {
405        // could use this if we wanted.
406    }
407
408    return 0;
409}
410
411const RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
412    .enc_name         = "H264",
413    .codec_type       = AVMEDIA_TYPE_VIDEO,
414    .codec_id         = AV_CODEC_ID_H264,
415    .need_parsing     = AVSTREAM_PARSE_FULL,
416    .priv_data_size   = sizeof(PayloadContext),
417    .parse_sdp_a_line = parse_h264_sdp_line,
418    .close            = h264_close_context,
419    .parse_packet     = h264_handle_packet,
420};