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1 /*
2  * RTP Depacketization of RAW video (TR-03)
3  * Copyright (c) 2016 Savoir-faire Linux, Inc
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 /* Development sponsored by CBC/Radio-Canada */
23 
24 #include "avio_internal.h"
25 #include "rtpdec_formats.h"
26 #include "libavutil/avstring.h"
27 #include "libavutil/pixdesc.h"
28 #include "libavutil/parseutils.h"
29 
30 struct PayloadContext {
31     char *sampling;
32     AVRational framerate;
33     int depth;
34     int width;
35     int height;
36     int interlaced;
37     int field;
38 
39     uint8_t *frame;
40     unsigned int frame_size;
41     unsigned int pgroup; /* size of the pixel group in bytes */
42     unsigned int xinc;
43 
44     uint32_t timestamp;
45 };
46 
rfc4175_parse_format(AVStream * stream,PayloadContext * data)47 static int rfc4175_parse_format(AVStream *stream, PayloadContext *data)
48 {
49     enum AVPixelFormat pixfmt;
50     int tag;
51     const AVPixFmtDescriptor *desc;
52 
53     if (!strncmp(data->sampling, "YCbCr-4:2:2", 11)) {
54         tag = MKTAG('U', 'Y', 'V', 'Y');
55         data->xinc = 2;
56 
57         if (data->depth == 8) {
58             data->pgroup = 4;
59             pixfmt = AV_PIX_FMT_UYVY422;
60             stream->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
61         } else if (data->depth == 10) {
62             data->pgroup = 5;
63             pixfmt = AV_PIX_FMT_YUV422P10;
64             stream->codecpar->codec_id = AV_CODEC_ID_BITPACKED;
65         } else {
66             return AVERROR_INVALIDDATA;
67         }
68     } else if (!strncmp(data->sampling, "YCbCr-4:2:0", 11)) {
69         tag = MKTAG('I', '4', '2', '0');
70         data->xinc = 4;
71 
72         if (data->depth == 8) {
73             data->pgroup = 6;
74             pixfmt = AV_PIX_FMT_YUV420P;
75             stream->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
76         } else {
77             return AVERROR_INVALIDDATA;
78         }
79     } else if (!strncmp(data->sampling, "RGB", 3)) {
80         tag = MKTAG('R', 'G', 'B', 24);
81         if (data->depth == 8) {
82             data->xinc = 1;
83             data->pgroup = 3;
84             pixfmt = AV_PIX_FMT_RGB24;
85             stream->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
86         } else {
87             return AVERROR_INVALIDDATA;
88         }
89     } else if (!strncmp(data->sampling, "BGR", 3)) {
90         tag = MKTAG('B', 'G', 'R', 24);
91         if (data->depth == 8) {
92             data->xinc = 1;
93             data->pgroup = 3;
94             pixfmt = AV_PIX_FMT_BGR24;
95             stream->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
96         } else {
97             return AVERROR_INVALIDDATA;
98         }
99     } else {
100         return AVERROR_INVALIDDATA;
101     }
102 
103     desc = av_pix_fmt_desc_get(pixfmt);
104     stream->codecpar->format = pixfmt;
105     stream->codecpar->codec_tag = tag;
106     stream->codecpar->bits_per_coded_sample = av_get_bits_per_pixel(desc);
107     data->frame_size = data->width * data->height * data->pgroup / data->xinc;
108 
109     if (data->interlaced)
110         stream->codecpar->field_order = AV_FIELD_TT;
111     else
112         stream->codecpar->field_order = AV_FIELD_PROGRESSIVE;
113 
114     if (data->framerate.den > 0) {
115         stream->avg_frame_rate = data->framerate;
116         stream->codecpar->bit_rate = data->frame_size * av_q2d(data->framerate) * 8;
117     }
118 
119     return 0;
120 }
121 
rfc4175_parse_fmtp(AVFormatContext * s,AVStream * stream,PayloadContext * data,const char * attr,const char * value)122 static int rfc4175_parse_fmtp(AVFormatContext *s, AVStream *stream,
123                               PayloadContext *data, const char *attr,
124                               const char *value)
125 {
126     if (!strncmp(attr, "width", 5))
127         data->width = atoi(value);
128     else if (!strncmp(attr, "height", 6))
129         data->height = atoi(value);
130     else if (!strncmp(attr, "sampling", 8))
131         data->sampling = av_strdup(value);
132     else if (!strncmp(attr, "depth", 5))
133         data->depth = atoi(value);
134     else if (!strncmp(attr, "interlace", 9))
135         data->interlaced = 1;
136     else if (!strncmp(attr, "exactframerate", 14)) {
137         if (av_parse_video_rate(&data->framerate, value) < 0)
138             return AVERROR(EINVAL);
139     } else if (!strncmp(attr, "TCS", 3)) {
140         if (!strncmp(value, "SDR", 3))
141             stream->codecpar->color_trc = AVCOL_TRC_BT709;
142         else if (!strncmp(value, "PQ", 2))
143             stream->codecpar->color_trc = AVCOL_TRC_SMPTE2084;
144         else if (!strncmp(value, "HLG", 3))
145             stream->codecpar->color_trc = AVCOL_TRC_ARIB_STD_B67;
146         else if (!strncmp(value, "LINEAR", 6))
147             stream->codecpar->color_trc = AVCOL_TRC_LINEAR;
148         else if (!strncmp(value, "ST428-1", 7))
149             stream->codecpar->color_trc = AVCOL_TRC_SMPTEST428_1;
150         else
151             stream->codecpar->color_trc = AVCOL_TRC_UNSPECIFIED;
152     } else if (!strncmp(attr, "colorimetry", 11)) {
153         if (!strncmp(value, "BT601", 5)) {
154             stream->codecpar->color_primaries = AVCOL_PRI_BT470BG;
155             stream->codecpar->color_space     = AVCOL_SPC_BT470BG;
156         } else if (!strncmp(value, "BT709", 5)) {
157             stream->codecpar->color_primaries = AVCOL_PRI_BT709;
158             stream->codecpar->color_space     = AVCOL_SPC_BT709;
159         } else if (!strncmp(value, "BT2020", 6)) {
160             stream->codecpar->color_primaries = AVCOL_PRI_BT2020;
161             stream->codecpar->color_space     = AVCOL_SPC_BT2020_NCL;
162         }
163     } else if (!strncmp(attr, "RANGE", 5)) {
164         if (!strncmp(value, "NARROW", 6))
165             stream->codecpar->color_range = AVCOL_RANGE_MPEG;
166         else if (!strncmp(value, "FULL", 4))
167             stream->codecpar->color_range = AVCOL_RANGE_JPEG;
168     }
169 
170     return 0;
171 }
172 
rfc4175_parse_sdp_line(AVFormatContext * s,int st_index,PayloadContext * data,const char * line)173 static int rfc4175_parse_sdp_line(AVFormatContext *s, int st_index,
174                                   PayloadContext *data, const char *line)
175 {
176     const char *p;
177 
178     if (st_index < 0)
179         return 0;
180 
181     if (av_strstart(line, "fmtp:", &p)) {
182         AVStream *stream = s->streams[st_index];
183         int ret = ff_parse_fmtp(s, stream, data, p, rfc4175_parse_fmtp);
184 
185         if (ret < 0)
186             return ret;
187 
188 
189         if (!data->sampling || !data->depth || !data->width || !data->height)
190             return AVERROR(EINVAL);
191 
192         stream->codecpar->width = data->width;
193         stream->codecpar->height = data->height;
194 
195         ret = rfc4175_parse_format(stream, data);
196         av_freep(&data->sampling);
197 
198         return ret;
199     }
200 
201     return 0;
202 }
203 
rfc4175_finalize_packet(PayloadContext * data,AVPacket * pkt,int stream_index)204 static int rfc4175_finalize_packet(PayloadContext *data, AVPacket *pkt,
205                                    int stream_index)
206 {
207     int ret = 0;
208 
209     pkt->stream_index = stream_index;
210     if (!data->interlaced || data->field) {
211         ret = av_packet_from_data(pkt, data->frame, data->frame_size);
212         if (ret < 0) {
213             av_freep(&data->frame);
214         }
215         data->frame = NULL;
216     }
217 
218     data->field = 0;
219 
220     return ret;
221 }
222 
rfc4175_handle_packet(AVFormatContext * ctx,PayloadContext * data,AVStream * st,AVPacket * pkt,uint32_t * timestamp,const uint8_t * buf,int len,uint16_t seq,int flags)223 static int rfc4175_handle_packet(AVFormatContext *ctx, PayloadContext *data,
224                                  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
225                                  const uint8_t * buf, int len,
226                                  uint16_t seq, int flags)
227 {
228     int length, line, offset, cont, field;
229     const uint8_t *headers = buf + 2; /* skip extended seqnum */
230     const uint8_t *payload = buf + 2;
231     int payload_len = len - 2;
232     int missed_last_packet = 0;
233 
234     uint8_t *dest;
235 
236     if (*timestamp != data->timestamp) {
237         if (data->frame && (!data->interlaced || data->field)) {
238             /*
239              * if we're here, it means that we missed the cue to return
240              * the previous AVPacket, that cue being the RTP_FLAG_MARKER
241              * in the last packet of either the previous frame (progressive)
242              * or the previous second field (interlace). Let's finalize the
243              * previous frame (or pair of fields) anyway by filling the AVPacket.
244              */
245             av_log(ctx, AV_LOG_ERROR, "Missed previous RTP Marker\n");
246             missed_last_packet = 1;
247             rfc4175_finalize_packet(data, pkt, st->index);
248         }
249 
250         if (!data->frame)
251             data->frame = av_malloc(data->frame_size);
252 
253         data->timestamp = *timestamp;
254 
255         if (!data->frame) {
256             av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
257             return AVERROR(ENOMEM);
258         }
259     }
260 
261     /*
262      * looks for the 'Continuation bit' in scan lines' headers
263      * to find where data start
264      */
265     do {
266         if (payload_len < 6)
267             return AVERROR_INVALIDDATA;
268 
269         cont = payload[4] & 0x80;
270         payload += 6;
271         payload_len -= 6;
272     } while (cont);
273 
274     /* and now iterate over every scan lines */
275     do {
276         int copy_offset;
277 
278         if (payload_len < data->pgroup)
279             return AVERROR_INVALIDDATA;
280 
281         length = (headers[0] << 8) | headers[1];
282         field = (headers[2] & 0x80) >> 7;
283         line = ((headers[2] & 0x7f) << 8) | headers[3];
284         offset = ((headers[4] & 0x7f) << 8) | headers[5];
285         cont = headers[4] & 0x80;
286         headers += 6;
287         data->field = field;
288 
289         if (!data->pgroup || length % data->pgroup)
290             return AVERROR_INVALIDDATA;
291 
292         if (length > payload_len)
293             length = payload_len;
294 
295         if (data->interlaced)
296             line = 2 * line + field;
297 
298         /* prevent ill-formed packets to write after buffer's end */
299         copy_offset = (line * data->width + offset) * data->pgroup / data->xinc;
300         if (copy_offset + length > data->frame_size || !data->frame)
301             return AVERROR_INVALIDDATA;
302 
303         dest = data->frame + copy_offset;
304         memcpy(dest, payload, length);
305 
306         payload += length;
307         payload_len -= length;
308     } while (cont);
309 
310     if ((flags & RTP_FLAG_MARKER)) {
311         return rfc4175_finalize_packet(data, pkt, st->index);
312     } else if (missed_last_packet) {
313         return 0;
314     }
315 
316     return AVERROR(EAGAIN);
317 }
318 
319 const RTPDynamicProtocolHandler ff_rfc4175_rtp_handler = {
320     .enc_name           = "raw",
321     .codec_type         = AVMEDIA_TYPE_VIDEO,
322     .codec_id           = AV_CODEC_ID_NONE,
323     .priv_data_size     = sizeof(PayloadContext),
324     .parse_sdp_a_line   = rfc4175_parse_sdp_line,
325     .parse_packet       = rfc4175_handle_packet,
326 };
327