2 * RTP JPEG-compressed Video Depacketizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
5 * This file is part of FFmpeg.
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.
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.
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
24 #include "rtpdec_formats.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavcodec/mjpeg.h"
27 #include "libavcodec/bytestream.h"
30 * RTP/JPEG specific private data.
32 struct PayloadContext {
33 AVIOContext *frame; ///< current frame buffer
34 uint32_t timestamp; ///< current frame timestamp
35 int hdr_size; ///< size of the current frame header
36 uint8_t qtables[128][128];
37 uint8_t qtables_len[128];
40 static const uint8_t default_quantizers[128] = {
42 16, 11, 12, 14, 12, 10, 16, 14,
43 13, 14, 18, 17, 16, 19, 24, 40,
44 26, 24, 22, 22, 24, 49, 35, 37,
45 29, 40, 58, 51, 61, 60, 57, 51,
46 56, 55, 64, 72, 92, 78, 64, 68,
47 87, 69, 55, 56, 80, 109, 81, 87,
48 95, 98, 103, 104, 103, 62, 77, 113,
49 121, 112, 100, 120, 92, 101, 103, 99,
52 17, 18, 18, 24, 21, 24, 47, 26,
53 26, 47, 99, 66, 56, 66, 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 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
62 static inline void free_frame(PayloadContext *jpeg)
66 avio_close_dyn_buf(jpeg->frame, &p);
72 static void jpeg_free_context(PayloadContext *jpeg)
78 static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
79 int table_id, const uint8_t *bits_table,
80 const uint8_t *value_table)
84 bytestream2_put_byte(p, table_class << 4 | table_id);
86 for (i = 1; i <= 16; i++) {
88 bytestream2_put_byte(p, bits_table[i]);
91 for (i = 0; i < n; i++) {
92 bytestream2_put_byte(p, value_table[i]);
97 static void jpeg_put_marker(PutByteContext *pbc, int code)
99 bytestream2_put_byte(pbc, 0xff);
100 bytestream2_put_byte(pbc, code);
103 static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
104 uint32_t h, const uint8_t *qtable, int nb_qtable,
108 uint8_t *dht_size_ptr;
111 bytestream2_init_writer(&pbc, buf, size);
113 /* Convert from blocks to pixels. */
118 jpeg_put_marker(&pbc, SOI);
121 jpeg_put_marker(&pbc, APP0);
122 bytestream2_put_be16(&pbc, 16);
123 bytestream2_put_buffer(&pbc, "JFIF", 5);
124 bytestream2_put_be16(&pbc, 0x0201);
125 bytestream2_put_byte(&pbc, 0);
126 bytestream2_put_be16(&pbc, 1);
127 bytestream2_put_be16(&pbc, 1);
128 bytestream2_put_byte(&pbc, 0);
129 bytestream2_put_byte(&pbc, 0);
132 jpeg_put_marker(&pbc, DRI);
133 bytestream2_put_be16(&pbc, 4);
134 bytestream2_put_be16(&pbc, dri);
138 jpeg_put_marker(&pbc, DQT);
139 bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
141 for (i = 0; i < nb_qtable; i++) {
142 bytestream2_put_byte(&pbc, i);
144 /* Each table is an array of 64 values given in zig-zag
145 * order, identical to the format used in a JFIF DQT
147 bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
151 jpeg_put_marker(&pbc, DHT);
152 dht_size_ptr = pbc.buffer;
153 bytestream2_put_be16(&pbc, 0);
156 dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
157 avpriv_mjpeg_val_dc);
158 dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
159 avpriv_mjpeg_val_dc);
160 dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
161 avpriv_mjpeg_val_ac_luminance);
162 dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
163 avpriv_mjpeg_val_ac_chrominance);
164 AV_WB16(dht_size_ptr, dht_size);
167 jpeg_put_marker(&pbc, SOF0);
168 bytestream2_put_be16(&pbc, 17); /* size */
169 bytestream2_put_byte(&pbc, 8); /* bits per component */
170 bytestream2_put_be16(&pbc, h);
171 bytestream2_put_be16(&pbc, w);
172 bytestream2_put_byte(&pbc, 3); /* number of components */
173 bytestream2_put_byte(&pbc, 1); /* component number */
174 bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
175 bytestream2_put_byte(&pbc, 0); /* matrix number */
176 bytestream2_put_byte(&pbc, 2); /* component number */
177 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
178 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
179 bytestream2_put_byte(&pbc, 3); /* component number */
180 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
181 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
184 jpeg_put_marker(&pbc, SOS);
185 bytestream2_put_be16(&pbc, 12);
186 bytestream2_put_byte(&pbc, 3);
187 bytestream2_put_byte(&pbc, 1);
188 bytestream2_put_byte(&pbc, 0);
189 bytestream2_put_byte(&pbc, 2);
190 bytestream2_put_byte(&pbc, 17);
191 bytestream2_put_byte(&pbc, 3);
192 bytestream2_put_byte(&pbc, 17);
193 bytestream2_put_byte(&pbc, 0);
194 bytestream2_put_byte(&pbc, 63);
195 bytestream2_put_byte(&pbc, 0);
197 /* Return the length in bytes of the JPEG header. */
198 return bytestream2_tell_p(&pbc);
201 static void create_default_qtables(uint8_t *qtables, uint8_t q)
206 factor = av_clip(q, 1, 99);
211 q = 200 - factor * 2;
213 for (i = 0; i < 128; i++) {
214 int val = (default_quantizers[i] * q + 50) / 100;
216 /* Limit the quantizers to 1 <= q <= 255. */
217 val = av_clip(val, 1, 255);
222 static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
223 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
224 const uint8_t *buf, int len, uint16_t seq,
227 uint8_t type, q, width, height;
228 const uint8_t *qtables = NULL;
234 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
235 return AVERROR_INVALIDDATA;
238 /* Parse the main JPEG header. */
239 off = AV_RB24(buf + 1); /* fragment byte offset */
240 type = AV_RB8(buf + 4); /* id of jpeg decoder params */
241 q = AV_RB8(buf + 5); /* quantization factor (or table id) */
242 width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
243 height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
249 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
250 return AVERROR_INVALIDDATA;
257 /* Parse the restart marker header. */
259 av_log(ctx, AV_LOG_ERROR,
260 "Unimplemented RTP/JPEG restart marker header.\n");
261 return AVERROR_PATCHWELCOME;
264 av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
265 return AVERROR_PATCHWELCOME;
268 /* Parse the quantization table header. */
270 /* Start of JPEG data packet. */
271 uint8_t new_qtables[128];
277 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
278 return AVERROR_INVALIDDATA;
281 /* The first byte is reserved for future use. */
282 precision = AV_RB8(buf + 1); /* size of coefficients */
283 qtable_len = AV_RB16(buf + 2); /* length in bytes */
288 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
290 if (qtable_len > 0) {
291 if (len < qtable_len) {
292 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
293 return AVERROR_INVALIDDATA;
299 if (jpeg->qtables_len[q - 128] &&
300 (jpeg->qtables_len[q - 128] != qtable_len ||
301 memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
302 av_log(ctx, AV_LOG_WARNING,
303 "Quantization tables for q=%d changed\n", q);
304 } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
305 memcpy(&jpeg->qtables[q - 128][0], qtables,
307 jpeg->qtables_len[q - 128] = qtable_len;
312 av_log(ctx, AV_LOG_ERROR,
313 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
314 return AVERROR_INVALIDDATA;
316 if (!jpeg->qtables_len[q - 128]) {
317 av_log(ctx, AV_LOG_ERROR,
318 "No quantization tables known for q=%d yet.\n", q);
319 return AVERROR_INVALIDDATA;
321 qtables = &jpeg->qtables[q - 128][0];
322 qtable_len = jpeg->qtables_len[q - 128];
324 } else { /* q <= 127 */
325 if (q == 0 || q > 99) {
326 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
327 return AVERROR_INVALIDDATA;
329 create_default_qtables(new_qtables, q);
330 qtables = new_qtables;
331 qtable_len = sizeof(new_qtables);
334 /* Skip the current frame in case of the end packet
335 * has been lost somewhere. */
338 if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
340 jpeg->timestamp = *timestamp;
342 /* Generate a frame and scan headers that can be prepended to the
343 * RTP/JPEG data payload to produce a JPEG compressed image in
344 * interchange format. */
345 jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
347 qtable_len / 64, dri);
349 /* Copy JPEG header to frame buffer. */
350 avio_write(jpeg->frame, hdr, jpeg->hdr_size);
354 av_log(ctx, AV_LOG_ERROR,
355 "Received packet without a start chunk; dropping frame.\n");
356 return AVERROR(EAGAIN);
359 if (jpeg->timestamp != *timestamp) {
360 /* Skip the current frame if timestamp is incorrect.
361 * A start packet has been lost somewhere. */
363 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
364 return AVERROR_INVALIDDATA;
367 if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
368 av_log(ctx, AV_LOG_ERROR,
369 "Missing packets; dropping frame.\n");
370 return AVERROR(EAGAIN);
373 /* Copy data to frame buffer. */
374 avio_write(jpeg->frame, buf, len);
376 if (flags & RTP_FLAG_MARKER) {
377 /* End of JPEG data packet. */
378 uint8_t buf[2] = { 0xff, EOI };
380 /* Put EOI marker. */
381 avio_write(jpeg->frame, buf, sizeof(buf));
383 /* Prepare the JPEG packet. */
384 if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
385 av_log(ctx, AV_LOG_ERROR,
386 "Error occurred when getting frame buffer.\n");
393 return AVERROR(EAGAIN);
396 RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
398 .codec_type = AVMEDIA_TYPE_VIDEO,
399 .codec_id = AV_CODEC_ID_MJPEG,
400 .priv_data_size = sizeof(PayloadContext),
401 .free = jpeg_free_context,
402 .parse_packet = jpeg_parse_packet,
403 .static_payload_id = 26,