rtpdec_jpeg: Simplify the calculation of the number of qtables
[libav.git] / libavformat / rtpdec_jpeg.c
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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 "rtpdec_formats.h"
24#include "libavutil/intreadwrite.h"
25#include "libavcodec/mjpeg.h"
20f325f3 26#include "libavcodec/bytestream.h"
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27
28/**
29 * RTP/JPEG specific private data.
30 */
31struct PayloadContext {
32 AVIOContext *frame; ///< current frame buffer
33 uint32_t timestamp; ///< current frame timestamp
34 int hdr_size; ///< size of the current frame header
35};
36
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37static const uint8_t default_quantizers[128] = {
38 /* luma table */
39 16, 11, 12, 14, 12, 10, 16, 14,
40 13, 14, 18, 17, 16, 19, 24, 40,
41 26, 24, 22, 22, 24, 49, 35, 37,
42 29, 40, 58, 51, 61, 60, 57, 51,
43 56, 55, 64, 72, 92, 78, 64, 68,
44 87, 69, 55, 56, 80, 109, 81, 87,
45 95, 98, 103, 104, 103, 62, 77, 113,
46 121, 112, 100, 120, 92, 101, 103, 99,
47
48 /* chroma table */
49 17, 18, 18, 24, 21, 24, 47, 26,
50 26, 47, 99, 66, 56, 66, 99, 99,
51 99, 99, 99, 99, 99, 99, 99, 99,
52 99, 99, 99, 99, 99, 99, 99, 99,
53 99, 99, 99, 99, 99, 99, 99, 99,
54 99, 99, 99, 99, 99, 99, 99, 99,
55 99, 99, 99, 99, 99, 99, 99, 99,
56 99, 99, 99, 99, 99, 99, 99, 99
57};
58
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59static PayloadContext *jpeg_new_context(void)
60{
61 return av_mallocz(sizeof(PayloadContext));
62}
63
64static inline void free_frame_if_needed(PayloadContext *jpeg)
65{
66 if (jpeg->frame) {
67 uint8_t *p;
68 avio_close_dyn_buf(jpeg->frame, &p);
69 av_free(p);
70 jpeg->frame = NULL;
71 }
72}
73
74static void jpeg_free_context(PayloadContext *jpeg)
75{
76 free_frame_if_needed(jpeg);
77 av_free(jpeg);
78}
79
20f325f3 80static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
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81 int table_id, const uint8_t *bits_table,
82 const uint8_t *value_table)
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83{
84 int i, n = 0;
85
20f325f3 86 bytestream2_put_byte(p, table_class << 4 | table_id);
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87
88 for (i = 1; i <= 16; i++) {
89 n += bits_table[i];
20f325f3 90 bytestream2_put_byte(p, bits_table[i]);
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91 }
92
93 for (i = 0; i < n; i++) {
20f325f3 94 bytestream2_put_byte(p, value_table[i]);
3c198154 95 }
7ef43234 96 return n + 17;
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97}
98
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99static void jpeg_put_marker(PutByteContext *pbc, int code)
100{
101 bytestream2_put_byte(pbc, 0xff);
102 bytestream2_put_byte(pbc, code);
103}
104
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105static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
106 uint32_t h, const uint8_t *qtable, int nb_qtable)
107{
20f325f3 108 PutByteContext pbc;
7ef43234 109 uint8_t *dht_size_ptr;
43957fcc 110 int dht_size, i;
3c198154 111
20f325f3 112 bytestream2_init_writer(&pbc, buf, size);
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113
114 /* Convert from blocks to pixels. */
115 w <<= 3;
116 h <<= 3;
117
118 /* SOI */
20f325f3 119 jpeg_put_marker(&pbc, SOI);
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120
121 /* JFIF header */
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122 jpeg_put_marker(&pbc, APP0);
123 bytestream2_put_be16(&pbc, 16);
124 bytestream2_put_buffer(&pbc, "JFIF", 5);
125 bytestream2_put_be16(&pbc, 0x0201);
126 bytestream2_put_byte(&pbc, 0);
127 bytestream2_put_be16(&pbc, 1);
128 bytestream2_put_be16(&pbc, 1);
129 bytestream2_put_byte(&pbc, 0);
130 bytestream2_put_byte(&pbc, 0);
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131
132 /* DQT */
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133 jpeg_put_marker(&pbc, DQT);
134 bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
3c198154 135
43957fcc 136 for (i = 0; i < nb_qtable; i++) {
20f325f3 137 bytestream2_put_byte(&pbc, i);
3c198154 138
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139 /* Each table is an array of 64 values given in zig-zag
140 * order, identical to the format used in a JFIF DQT
141 * marker segment. */
20f325f3 142 bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
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143 }
144
145 /* DHT */
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146 jpeg_put_marker(&pbc, DHT);
147 dht_size_ptr = pbc.buffer;
148 bytestream2_put_be16(&pbc, 0);
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149
150 dht_size = 2;
151 dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
152 avpriv_mjpeg_val_dc);
153 dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
154 avpriv_mjpeg_val_dc);
155 dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
156 avpriv_mjpeg_val_ac_luminance);
157 dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
158 avpriv_mjpeg_val_ac_chrominance);
159 AV_WB16(dht_size_ptr, dht_size);
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160
161 /* SOF0 */
20f325f3 162 jpeg_put_marker(&pbc, SOF0);
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163 bytestream2_put_be16(&pbc, 17); /* size */
164 bytestream2_put_byte(&pbc, 8); /* bits per component */
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165 bytestream2_put_be16(&pbc, h);
166 bytestream2_put_be16(&pbc, w);
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167 bytestream2_put_byte(&pbc, 3); /* number of components */
168 bytestream2_put_byte(&pbc, 1); /* component number */
31adff08 169 bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
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170 bytestream2_put_byte(&pbc, 0); /* matrix number */
171 bytestream2_put_byte(&pbc, 2); /* component number */
31adff08 172 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
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173 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
174 bytestream2_put_byte(&pbc, 3); /* component number */
31adff08 175 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
cbaa9eed 176 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
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177
178 /* SOS */
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179 jpeg_put_marker(&pbc, SOS);
180 bytestream2_put_be16(&pbc, 12);
181 bytestream2_put_byte(&pbc, 3);
182 bytestream2_put_byte(&pbc, 1);
183 bytestream2_put_byte(&pbc, 0);
184 bytestream2_put_byte(&pbc, 2);
185 bytestream2_put_byte(&pbc, 17);
186 bytestream2_put_byte(&pbc, 3);
187 bytestream2_put_byte(&pbc, 17);
188 bytestream2_put_byte(&pbc, 0);
189 bytestream2_put_byte(&pbc, 63);
190 bytestream2_put_byte(&pbc, 0);
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191
192 /* Return the length in bytes of the JPEG header. */
20f325f3 193 return bytestream2_tell_p(&pbc);
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194}
195
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196static void create_default_qtables(uint8_t *qtables, uint8_t q)
197{
198 int factor = q;
199 int i;
200
201 factor = av_clip(q, 1, 99);
202
203 if (q < 50)
204 q = 5000 / factor;
205 else
206 q = 200 - factor * 2;
207
208 for (i = 0; i < 128; i++) {
209 int val = (default_quantizers[i] * q + 50) / 100;
210
211 /* Limit the quantizers to 1 <= q <= 255. */
212 val = av_clip(val, 1, 255);
213 qtables[i] = val;
214 }
215}
216
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217static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
218 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
219 const uint8_t *buf, int len, int flags)
220{
221 uint8_t type, q, width, height;
222 const uint8_t *qtables = NULL;
223 uint16_t qtable_len;
224 uint32_t off;
225 int ret;
226
227 if (len < 8) {
228 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
229 return AVERROR_INVALIDDATA;
230 }
231
232 /* Parse the main JPEG header. */
233 off = AV_RB24(buf + 1); /* fragment byte offset */
234 type = AV_RB8(buf + 4); /* id of jpeg decoder params */
235 q = AV_RB8(buf + 5); /* quantization factor (or table id) */
236 width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
237 height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
238 buf += 8;
239 len -= 8;
240
241 /* Parse the restart marker header. */
242 if (type > 63) {
243 av_log(ctx, AV_LOG_ERROR,
244 "Unimplemented RTP/JPEG restart marker header.\n");
245 return AVERROR_PATCHWELCOME;
246 }
247
248 /* Parse the quantization table header. */
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249 if (off == 0) {
250 /* Start of JPEG data packet. */
251 uint8_t new_qtables[128];
252 uint8_t hdr[1024];
3c198154 253
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254 if (q > 127) {
255 uint8_t precision;
256 if (len < 4) {
257 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
258 return AVERROR_INVALIDDATA;
259 }
3c198154 260
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261 /* The first byte is reserved for future use. */
262 precision = AV_RB8(buf + 1); /* size of coefficients */
263 qtable_len = AV_RB16(buf + 2); /* length in bytes */
264 buf += 4;
265 len -= 4;
3c198154 266
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267 if (precision)
268 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
3c198154 269
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270 if (q == 255 && qtable_len == 0) {
271 av_log(ctx, AV_LOG_ERROR,
272 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
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273 return AVERROR_INVALIDDATA;
274 }
3c198154 275
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276 if (qtable_len > 0) {
277 if (len < qtable_len) {
278 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
279 return AVERROR_INVALIDDATA;
280 }
281 qtables = buf;
282 buf += qtable_len;
283 len -= qtable_len;
284 }
285 }
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286
287 /* Skip the current frame in case of the end packet
288 * has been lost somewhere. */
289 free_frame_if_needed(jpeg);
290
291 if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
292 return ret;
293 jpeg->timestamp = *timestamp;
294
295 if (!qtables) {
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296 create_default_qtables(new_qtables, q);
297 qtables = new_qtables;
298 qtable_len = sizeof(new_qtables);
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299 }
300
301 /* Generate a frame and scan headers that can be prepended to the
302 * RTP/JPEG data payload to produce a JPEG compressed image in
303 * interchange format. */
304 jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
305 height, qtables,
a2526490 306 qtable_len / 64);
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307
308 /* Copy JPEG header to frame buffer. */
309 avio_write(jpeg->frame, hdr, jpeg->hdr_size);
310 }
311
312 if (!jpeg->frame) {
313 av_log(ctx, AV_LOG_ERROR,
314 "Received packet without a start chunk; dropping frame.\n");
315 return AVERROR(EAGAIN);
316 }
317
318 if (jpeg->timestamp != *timestamp) {
319 /* Skip the current frame if timestamp is incorrect.
320 * A start packet has been lost somewhere. */
321 free_frame_if_needed(jpeg);
322 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
323 return AVERROR_INVALIDDATA;
324 }
325
326 if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
327 av_log(ctx, AV_LOG_ERROR,
328 "Missing packets; dropping frame.\n");
329 return AVERROR(EAGAIN);
330 }
331
332 /* Copy data to frame buffer. */
333 avio_write(jpeg->frame, buf, len);
334
335 if (flags & RTP_FLAG_MARKER) {
336 /* End of JPEG data packet. */
c64d2a63 337 uint8_t buf[2] = { 0xff, EOI };
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338
339 /* Put EOI marker. */
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340 avio_write(jpeg->frame, buf, sizeof(buf));
341
342 /* Prepare the JPEG packet. */
343 av_init_packet(pkt);
344 pkt->size = avio_close_dyn_buf(jpeg->frame, &pkt->data);
345 if (pkt->size < 0) {
346 av_log(ctx, AV_LOG_ERROR,
347 "Error occured when getting frame buffer.\n");
348 jpeg->frame = NULL;
349 return pkt->size;
350 }
351 pkt->stream_index = st->index;
352 pkt->destruct = av_destruct_packet;
353
354 /* Re-init the frame buffer. */
355 jpeg->frame = NULL;
356
357 return 0;
358 }
359
360 return AVERROR(EAGAIN);
361}
362
363RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
364 .enc_name = "JPEG",
365 .codec_type = AVMEDIA_TYPE_VIDEO,
366 .codec_id = AV_CODEC_ID_MJPEG,
367 .alloc = jpeg_new_context,
368 .free = jpeg_free_context,
369 .parse_packet = jpeg_parse_packet,
370 .static_payload_id = 26,
371};