rtpdec_jpeg: Coalesce redundant error checks
[libav.git] / libavformat / rtpdec_jpeg.c
1 /*
2 * RTP JPEG-compressed Video Depacketizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 {
97 PutByteContext pbc;
98 uint8_t *dht_size_ptr;
99 int dht_size, i;
100
101 bytestream2_init_writer(&pbc, buf, size);
102
103 /* Convert from blocks to pixels. */
104 w <<= 3;
105 h <<= 3;
106
107 /* SOI */
108 jpeg_put_marker(&pbc, SOI);
109
110 /* JFIF header */
111 jpeg_put_marker(&pbc, APP0);
112 bytestream2_put_be16(&pbc, 16);
113 bytestream2_put_buffer(&pbc, "JFIF", 5);
114 bytestream2_put_be16(&pbc, 0x0201);
115 bytestream2_put_byte(&pbc, 0);
116 bytestream2_put_be16(&pbc, 1);
117 bytestream2_put_be16(&pbc, 1);
118 bytestream2_put_byte(&pbc, 0);
119 bytestream2_put_byte(&pbc, 0);
120
121 /* DQT */
122 jpeg_put_marker(&pbc, DQT);
123 bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
124
125 for (i = 0; i < nb_qtable; i++) {
126 bytestream2_put_byte(&pbc, i);
127
128 /* Each table is an array of 64 values given in zig-zag
129 * order, identical to the format used in a JFIF DQT
130 * marker segment. */
131 bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
132 }
133
134 /* DHT */
135 jpeg_put_marker(&pbc, DHT);
136 dht_size_ptr = pbc.buffer;
137 bytestream2_put_be16(&pbc, 0);
138
139 dht_size = 2;
140 dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
141 avpriv_mjpeg_val_dc);
142 dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
143 avpriv_mjpeg_val_dc);
144 dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
145 avpriv_mjpeg_val_ac_luminance);
146 dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
147 avpriv_mjpeg_val_ac_chrominance);
148 AV_WB16(dht_size_ptr, dht_size);
149
150 /* SOF0 */
151 jpeg_put_marker(&pbc, SOF0);
152 bytestream2_put_be16(&pbc, 17); /* size */
153 bytestream2_put_byte(&pbc, 8); /* bits per component */
154 bytestream2_put_be16(&pbc, h);
155 bytestream2_put_be16(&pbc, w);
156 bytestream2_put_byte(&pbc, 3); /* number of components */
157 bytestream2_put_byte(&pbc, 1); /* component number */
158 bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
159 bytestream2_put_byte(&pbc, 0); /* matrix number */
160 bytestream2_put_byte(&pbc, 2); /* component number */
161 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
162 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
163 bytestream2_put_byte(&pbc, 3); /* component number */
164 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
165 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
166
167 /* SOS */
168 jpeg_put_marker(&pbc, SOS);
169 bytestream2_put_be16(&pbc, 12);
170 bytestream2_put_byte(&pbc, 3);
171 bytestream2_put_byte(&pbc, 1);
172 bytestream2_put_byte(&pbc, 0);
173 bytestream2_put_byte(&pbc, 2);
174 bytestream2_put_byte(&pbc, 17);
175 bytestream2_put_byte(&pbc, 3);
176 bytestream2_put_byte(&pbc, 17);
177 bytestream2_put_byte(&pbc, 0);
178 bytestream2_put_byte(&pbc, 63);
179 bytestream2_put_byte(&pbc, 0);
180
181 /* Return the length in bytes of the JPEG header. */
182 return bytestream2_tell_p(&pbc);
183 }
184
185 static void create_default_qtables(uint8_t *qtables, uint8_t q)
186 {
187 int factor = q;
188 int i;
189
190 factor = av_clip(q, 1, 99);
191
192 if (q < 50)
193 q = 5000 / factor;
194 else
195 q = 200 - factor * 2;
196
197 for (i = 0; i < 128; i++) {
198 int val = (default_quantizers[i] * q + 50) / 100;
199
200 /* Limit the quantizers to 1 <= q <= 255. */
201 val = av_clip(val, 1, 255);
202 qtables[i] = val;
203 }
204 }
205
206 static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
207 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
208 const uint8_t *buf, int len, uint16_t seq,
209 int flags)
210 {
211 uint8_t type, q, width, height;
212 const uint8_t *qtables = NULL;
213 uint16_t qtable_len;
214 uint32_t off;
215 int ret;
216
217 if (len < 8) {
218 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
219 return AVERROR_INVALIDDATA;
220 }
221
222 /* Parse the main JPEG header. */
223 off = AV_RB24(buf + 1); /* fragment byte offset */
224 type = AV_RB8(buf + 4); /* id of jpeg decoder params */
225 q = AV_RB8(buf + 5); /* quantization factor (or table id) */
226 width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
227 height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
228 buf += 8;
229 len -= 8;
230
231 if (type > 1) {
232 av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
233 return AVERROR_PATCHWELCOME;
234 }
235
236 /* Parse the quantization table header. */
237 if (off == 0) {
238 /* Start of JPEG data packet. */
239 uint8_t new_qtables[128];
240 uint8_t hdr[1024];
241
242 if (q > 127) {
243 uint8_t precision;
244 if (len < 4) {
245 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
246 return AVERROR_INVALIDDATA;
247 }
248
249 /* The first byte is reserved for future use. */
250 precision = AV_RB8(buf + 1); /* size of coefficients */
251 qtable_len = AV_RB16(buf + 2); /* length in bytes */
252 buf += 4;
253 len -= 4;
254
255 if (precision)
256 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
257
258 if (qtable_len > 0) {
259 if (len < qtable_len) {
260 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
261 return AVERROR_INVALIDDATA;
262 }
263 qtables = buf;
264 buf += qtable_len;
265 len -= qtable_len;
266 if (q < 255) {
267 if (jpeg->qtables_len[q - 128] &&
268 (jpeg->qtables_len[q - 128] != qtable_len ||
269 memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
270 av_log(ctx, AV_LOG_WARNING,
271 "Quantization tables for q=%d changed\n", q);
272 } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
273 memcpy(&jpeg->qtables[q - 128][0], qtables,
274 qtable_len);
275 jpeg->qtables_len[q - 128] = qtable_len;
276 }
277 }
278 } else {
279 if (q == 255) {
280 av_log(ctx, AV_LOG_ERROR,
281 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
282 return AVERROR_INVALIDDATA;
283 }
284 if (!jpeg->qtables_len[q - 128]) {
285 av_log(ctx, AV_LOG_ERROR,
286 "No quantization tables known for q=%d yet.\n", q);
287 return AVERROR_INVALIDDATA;
288 }
289 qtables = &jpeg->qtables[q - 128][0];
290 qtable_len = jpeg->qtables_len[q - 128];
291 }
292 } else { /* q <= 127 */
293 if (q == 0 || q > 99) {
294 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
295 return AVERROR_INVALIDDATA;
296 }
297 create_default_qtables(new_qtables, q);
298 qtables = new_qtables;
299 qtable_len = sizeof(new_qtables);
300 }
301
302 /* Skip the current frame in case of the end packet
303 * has been lost somewhere. */
304 ffio_free_dyn_buf(&jpeg->frame);
305
306 if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
307 return ret;
308 jpeg->timestamp = *timestamp;
309
310 /* Generate a frame and scan headers that can be prepended to the
311 * RTP/JPEG data payload to produce a JPEG compressed image in
312 * interchange format. */
313 jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
314 height, qtables,
315 qtable_len / 64);
316
317 /* Copy JPEG header to frame buffer. */
318 avio_write(jpeg->frame, hdr, jpeg->hdr_size);
319 }
320
321 if (!jpeg->frame) {
322 av_log(ctx, AV_LOG_ERROR,
323 "Received packet without a start chunk; dropping frame.\n");
324 return AVERROR(EAGAIN);
325 }
326
327 if (jpeg->timestamp != *timestamp) {
328 /* Skip the current frame if timestamp is incorrect.
329 * A start packet has been lost somewhere. */
330 ffio_free_dyn_buf(&jpeg->frame);
331 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
332 return AVERROR_INVALIDDATA;
333 }
334
335 if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
336 av_log(ctx, AV_LOG_ERROR,
337 "Missing packets; dropping frame.\n");
338 return AVERROR(EAGAIN);
339 }
340
341 /* Copy data to frame buffer. */
342 avio_write(jpeg->frame, buf, len);
343
344 if (flags & RTP_FLAG_MARKER) {
345 /* End of JPEG data packet. */
346 uint8_t buf[2] = { 0xff, EOI };
347
348 /* Put EOI marker. */
349 avio_write(jpeg->frame, buf, sizeof(buf));
350
351 /* Prepare the JPEG packet. */
352 if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
353 av_log(ctx, AV_LOG_ERROR,
354 "Error occurred when getting frame buffer.\n");
355 return ret;
356 }
357
358 return 0;
359 }
360
361 return AVERROR(EAGAIN);
362 }
363
364 RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
365 .enc_name = "JPEG",
366 .codec_type = AVMEDIA_TYPE_VIDEO,
367 .codec_id = AV_CODEC_ID_MJPEG,
368 .priv_data_size = sizeof(PayloadContext),
369 .close = jpeg_close_context,
370 .parse_packet = jpeg_parse_packet,
371 .static_payload_id = 26,
372 };