FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/rtpdec_jpeg.c
Date: 2026-04-24 05:04:01
Exec Total Coverage
Lines: 0 178 0.0%
Functions: 0 6 0.0%
Branches: 0 66 0.0%
Line Branch Exec Source
1 /*
2 * RTP JPEG-compressed Video Depacketizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
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 #include "avformat.h"
23 #include "avio_internal.h"
24 #include "rtpdec.h"
25 #include "rtpdec_formats.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavcodec/jpegtables.h"
28 #include "libavcodec/mjpeg.h"
29 #include "libavcodec/bytestream.h"
30
31 /**
32 * RTP/JPEG specific private data.
33 */
34 struct PayloadContext {
35 AVIOContext *frame; ///< current frame buffer
36 uint32_t timestamp; ///< current frame timestamp
37 int hdr_size; ///< size of the current frame header
38 uint8_t qtables[128][128];
39 uint8_t qtables_len[128];
40 };
41
42 static const uint8_t default_quantizers[128] = {
43 /* luma table */
44 16, 11, 12, 14, 12, 10, 16, 14,
45 13, 14, 18, 17, 16, 19, 24, 40,
46 26, 24, 22, 22, 24, 49, 35, 37,
47 29, 40, 58, 51, 61, 60, 57, 51,
48 56, 55, 64, 72, 92, 78, 64, 68,
49 87, 69, 55, 56, 80, 109, 81, 87,
50 95, 98, 103, 104, 103, 62, 77, 113,
51 121, 112, 100, 120, 92, 101, 103, 99,
52
53 /* chroma table */
54 17, 18, 18, 24, 21, 24, 47, 26,
55 26, 47, 99, 66, 56, 66, 99, 99,
56 99, 99, 99, 99, 99, 99, 99, 99,
57 99, 99, 99, 99, 99, 99, 99, 99,
58 99, 99, 99, 99, 99, 99, 99, 99,
59 99, 99, 99, 99, 99, 99, 99, 99,
60 99, 99, 99, 99, 99, 99, 99, 99,
61 99, 99, 99, 99, 99, 99, 99, 99
62 };
63
64 ✗ static void jpeg_close_context(PayloadContext *jpeg)
65 {
66 ✗ ffio_free_dyn_buf(&jpeg->frame);
67 ✗ }
68
69 ✗ static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
70 int table_id, const uint8_t *bits_table,
71 const uint8_t *value_table)
72 {
73 ✗ int i, n = 0;
74
75 ✗ bytestream2_put_byte(p, table_class << 4 | table_id);
76
77 ✗ for (i = 1; i <= 16; i++) {
78 ✗ n += bits_table[i];
79 ✗ bytestream2_put_byte(p, bits_table[i]);
80 }
81
82 ✗ for (i = 0; i < n; i++) {
83 ✗ bytestream2_put_byte(p, value_table[i]);
84 }
85 ✗ return n + 17;
86 }
87
88 ✗ static void jpeg_put_marker(PutByteContext *pbc, int code)
89 {
90 ✗ bytestream2_put_byte(pbc, 0xff);
91 ✗ bytestream2_put_byte(pbc, code);
92 ✗ }
93
94 ✗ static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
95 uint32_t h, const uint8_t *qtable, int nb_qtable,
96 int dri)
97 {
98 PutByteContext pbc;
99 uint8_t *dht_size_ptr;
100 int dht_size, i;
101
102 ✗ bytestream2_init_writer(&pbc, buf, size);
103
104 /* Convert from blocks to pixels. */
105 ✗ w <<= 3;
106 ✗ h <<= 3;
107
108 /* SOI */
109 ✗ jpeg_put_marker(&pbc, SOI);
110
111 /* JFIF header */
112 ✗ jpeg_put_marker(&pbc, APP0);
113 ✗ bytestream2_put_be16(&pbc, 16);
114 ✗ bytestream2_put_buffer(&pbc, "JFIF", 5);
115 ✗ bytestream2_put_be16(&pbc, 0x0102);
116 ✗ bytestream2_put_byte(&pbc, 0);
117 ✗ bytestream2_put_be16(&pbc, 1);
118 ✗ bytestream2_put_be16(&pbc, 1);
119 ✗ bytestream2_put_byte(&pbc, 0);
120 ✗ bytestream2_put_byte(&pbc, 0);
121
122 ✗ if (dri) {
123 ✗ jpeg_put_marker(&pbc, DRI);
124 ✗ bytestream2_put_be16(&pbc, 4);
125 ✗ bytestream2_put_be16(&pbc, dri);
126 }
127
128 /* DQT */
129 ✗ jpeg_put_marker(&pbc, DQT);
130 ✗ bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
131
132 ✗ for (i = 0; i < nb_qtable; i++) {
133 ✗ bytestream2_put_byte(&pbc, i);
134
135 /* Each table is an array of 64 values given in zig-zag
136 * order, identical to the format used in a JFIF DQT
137 * marker segment. */
138 ✗ bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
139 }
140
141 /* DHT */
142 ✗ jpeg_put_marker(&pbc, DHT);
143 ✗ dht_size_ptr = pbc.buffer;
144 ✗ bytestream2_put_be16(&pbc, 0);
145
146 ✗ dht_size = 2;
147 ✗ dht_size += jpeg_create_huffman_table(&pbc, 0, 0,ff_mjpeg_bits_dc_luminance,
148 ff_mjpeg_val_dc);
149 ✗ dht_size += jpeg_create_huffman_table(&pbc, 0, 1, ff_mjpeg_bits_dc_chrominance,
150 ff_mjpeg_val_dc);
151 ✗ dht_size += jpeg_create_huffman_table(&pbc, 1, 0, ff_mjpeg_bits_ac_luminance,
152 ff_mjpeg_val_ac_luminance);
153 ✗ dht_size += jpeg_create_huffman_table(&pbc, 1, 1, ff_mjpeg_bits_ac_chrominance,
154 ff_mjpeg_val_ac_chrominance);
155 ✗ AV_WB16(dht_size_ptr, dht_size);
156
157 /* SOF0 */
158 ✗ jpeg_put_marker(&pbc, SOF0);
159 ✗ bytestream2_put_be16(&pbc, 17); /* size */
160 ✗ bytestream2_put_byte(&pbc, 8); /* bits per component */
161 ✗ bytestream2_put_be16(&pbc, h);
162 ✗ bytestream2_put_be16(&pbc, w);
163 ✗ bytestream2_put_byte(&pbc, 3); /* number of components */
164 ✗ bytestream2_put_byte(&pbc, 1); /* component number */
165 ✗ bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
166 ✗ bytestream2_put_byte(&pbc, 0); /* matrix number */
167 ✗ bytestream2_put_byte(&pbc, 2); /* component number */
168 ✗ bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
169 ✗ bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
170 ✗ bytestream2_put_byte(&pbc, 3); /* component number */
171 ✗ bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
172 ✗ bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
173
174 /* SOS */
175 ✗ jpeg_put_marker(&pbc, SOS);
176 ✗ bytestream2_put_be16(&pbc, 12);
177 ✗ bytestream2_put_byte(&pbc, 3);
178 ✗ bytestream2_put_byte(&pbc, 1);
179 ✗ bytestream2_put_byte(&pbc, 0);
180 ✗ bytestream2_put_byte(&pbc, 2);
181 ✗ bytestream2_put_byte(&pbc, 17);
182 ✗ bytestream2_put_byte(&pbc, 3);
183 ✗ bytestream2_put_byte(&pbc, 17);
184 ✗ bytestream2_put_byte(&pbc, 0);
185 ✗ bytestream2_put_byte(&pbc, 63);
186 ✗ bytestream2_put_byte(&pbc, 0);
187
188 /* Return the length in bytes of the JPEG header. */
189 ✗ return bytestream2_tell_p(&pbc);
190 }
191
192 ✗ static void create_default_qtables(uint8_t *qtables, uint8_t q)
193 {
194 ✗ int factor = q;
195 int i;
196 uint16_t S;
197
198 ✗ factor = av_clip(q, 1, 99);
199
200 ✗ if (q < 50)
201 ✗ S = 5000 / factor;
202 else
203 ✗ S = 200 - factor * 2;
204
205 ✗ for (i = 0; i < 128; i++) {
206 ✗ int val = (default_quantizers[i] * S + 50) / 100;
207
208 /* Limit the quantizers to 1 <= q <= 255. */
209 ✗ val = av_clip(val, 1, 255);
210 ✗ qtables[i] = val;
211 }
212 ✗ }
213
214 ✗ static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
215 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
216 const uint8_t *buf, int len, uint16_t seq,
217 int flags)
218 {
219 uint8_t type, q, width, height;
220 ✗ const uint8_t *qtables = NULL;
221 uint16_t qtable_len;
222 uint32_t off;
223 ✗ int ret, dri = 0;
224
225 ✗ if (len < 8) {
226 ✗ av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
227 ✗ return AVERROR_INVALIDDATA;
228 }
229
230 /* Parse the main JPEG header. */
231 ✗ off = AV_RB24(buf + 1); /* fragment byte offset */
232 ✗ type = AV_RB8(buf + 4); /* id of jpeg decoder params */
233 ✗ q = AV_RB8(buf + 5); /* quantization factor (or table id) */
234 ✗ width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
235 ✗ height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
236 ✗ st->codecpar->width = width*8;
237 ✗ st->codecpar->height = height*8;
238 ✗ buf += 8;
239 ✗ len -= 8;
240
241 ✗ if (type & 0x40) {
242 ✗ if (len < 4) {
243 ✗ av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
244 ✗ return AVERROR_INVALIDDATA;
245 }
246 ✗ dri = AV_RB16(buf);
247 ✗ buf += 4;
248 ✗ len -= 4;
249 ✗ type &= ~0x40;
250 }
251 ✗ if (type > 1) {
252 ✗ avpriv_report_missing_feature(ctx, "RTP/JPEG type %"PRIu8, type);
253 ✗ return AVERROR_PATCHWELCOME;
254 }
255
256 /* Parse the quantization table header. */
257 ✗ if (off == 0) {
258 /* Start of JPEG data packet. */
259 uint8_t new_qtables[128];
260 uint8_t hdr[1024];
261
262 ✗ if (q > 127) {
263 uint8_t precision;
264 ✗ if (len < 4) {
265 ✗ av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
266 ✗ return AVERROR_INVALIDDATA;
267 }
268
269 /* The first byte is reserved for future use. */
270 ✗ precision = AV_RB8(buf + 1); /* size of coefficients */
271 ✗ qtable_len = AV_RB16(buf + 2); /* length in bytes */
272 ✗ buf += 4;
273 ✗ len -= 4;
274
275 ✗ if (precision)
276 ✗ av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
277
278 ✗ if (qtable_len > 0) {
279 ✗ if (len < qtable_len) {
280 ✗ av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
281 ✗ return AVERROR_INVALIDDATA;
282 }
283 ✗ qtables = buf;
284 ✗ buf += qtable_len;
285 ✗ len -= qtable_len;
286 ✗ if (q < 255) {
287 ✗ if (jpeg->qtables_len[q - 128] &&
288 ✗ (jpeg->qtables_len[q - 128] != qtable_len ||
289 ✗ memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
290 ✗ av_log(ctx, AV_LOG_WARNING,
291 "Quantization tables for q=%d changed\n", q);
292 ✗ } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
293 ✗ memcpy(&jpeg->qtables[q - 128][0], qtables,
294 qtable_len);
295 ✗ jpeg->qtables_len[q - 128] = qtable_len;
296 }
297 }
298 } else {
299 ✗ if (q == 255) {
300 ✗ av_log(ctx, AV_LOG_ERROR,
301 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
302 ✗ return AVERROR_INVALIDDATA;
303 }
304 ✗ if (!jpeg->qtables_len[q - 128]) {
305 ✗ av_log(ctx, AV_LOG_ERROR,
306 "No quantization tables known for q=%d yet.\n", q);
307 ✗ return AVERROR_INVALIDDATA;
308 }
309 ✗ qtables = &jpeg->qtables[q - 128][0];
310 ✗ qtable_len = jpeg->qtables_len[q - 128];
311 }
312 } else { /* q <= 127 */
313 ✗ if (q == 0 || q > 99) {
314 ✗ av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
315 ✗ return AVERROR_INVALIDDATA;
316 }
317 ✗ create_default_qtables(new_qtables, q);
318 ✗ qtables = new_qtables;
319 ✗ qtable_len = sizeof(new_qtables);
320 }
321
322 /* Skip the current frame in case of the end packet
323 * has been lost somewhere. */
324 ✗ ffio_free_dyn_buf(&jpeg->frame);
325
326 ✗ if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
327 ✗ return ret;
328 ✗ jpeg->timestamp = *timestamp;
329
330 /* Generate a frame and scan headers that can be prepended to the
331 * RTP/JPEG data payload to produce a JPEG compressed image in
332 * interchange format. */
333 ✗ jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
334 height, qtables,
335 qtable_len / 64, dri);
336
337 /* Copy JPEG header to frame buffer. */
338 ✗ avio_write(jpeg->frame, hdr, jpeg->hdr_size);
339 }
340
341 ✗ if (!jpeg->frame) {
342 ✗ av_log(ctx, AV_LOG_ERROR,
343 "Received packet without a start chunk; dropping frame.\n");
344 ✗ return AVERROR(EAGAIN);
345 }
346
347 ✗ if (jpeg->timestamp != *timestamp) {
348 /* Skip the current frame if timestamp is incorrect.
349 * A start packet has been lost somewhere. */
350 ✗ ffio_free_dyn_buf(&jpeg->frame);
351 ✗ av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
352 ✗ return AVERROR_INVALIDDATA;
353 }
354
355 ✗ if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
356 ✗ av_log(ctx, AV_LOG_ERROR,
357 "Missing packets; dropping frame.\n");
358 ✗ return AVERROR(EAGAIN);
359 }
360
361 /* Copy data to frame buffer. */
362 ✗ avio_write(jpeg->frame, buf, len);
363
364 ✗ if (flags & RTP_FLAG_MARKER) {
365 /* End of JPEG data packet. */
366 ✗ uint8_t buf[2] = { 0xff, EOI };
367
368 /* Put EOI marker. */
369 ✗ avio_write(jpeg->frame, buf, sizeof(buf));
370
371 /* Prepare the JPEG packet. */
372 ✗ if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
373 ✗ av_log(ctx, AV_LOG_ERROR,
374 "Error occurred when getting frame buffer.\n");
375 ✗ return ret;
376 }
377
378 ✗ return 0;
379 }
380
381 ✗ return AVERROR(EAGAIN);
382 }
383
384 const RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
385 .enc_name = "JPEG",
386 .codec_type = AVMEDIA_TYPE_VIDEO,
387 .codec_id = AV_CODEC_ID_MJPEG,
388 .priv_data_size = sizeof(PayloadContext),
389 .close = jpeg_close_context,
390 .parse_packet = jpeg_parse_packet,
391 .static_payload_id = 26,
392 };
393