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
23 #include "avio_internal.h"
25 #include "rtpdec_formats.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavcodec/mjpeg.h"
28 #include "libavcodec/bytestream.h"
31 * RTP/JPEG specific private data.
33 struct PayloadContext {
34 AVIOContext *frame; ///< current frame buffer
35 uint32_t timestamp; ///< current frame timestamp
36 int hdr_size; ///< size of the current frame header
37 uint8_t qtables[128][128];
38 uint8_t qtables_len[128];
41 static const uint8_t default_quantizers[128] = {
43 16, 11, 12, 14, 12, 10, 16, 14,
44 13, 14, 18, 17, 16, 19, 24, 40,
45 26, 24, 22, 22, 24, 49, 35, 37,
46 29, 40, 58, 51, 61, 60, 57, 51,
47 56, 55, 64, 72, 92, 78, 64, 68,
48 87, 69, 55, 56, 80, 109, 81, 87,
49 95, 98, 103, 104, 103, 62, 77, 113,
50 121, 112, 100, 120, 92, 101, 103, 99,
53 17, 18, 18, 24, 21, 24, 47, 26,
54 26, 47, 99, 66, 56, 66, 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,
60 99, 99, 99, 99, 99, 99, 99, 99
63 static void jpeg_close_context(PayloadContext *jpeg)
65 ffio_free_dyn_buf(&jpeg->frame);
68 static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
69 int table_id, const uint8_t *bits_table,
70 const uint8_t *value_table)
74 bytestream2_put_byte(p, table_class << 4 | table_id);
76 for (i = 1; i <= 16; i++) {
78 bytestream2_put_byte(p, bits_table[i]);
81 for (i = 0; i < n; i++) {
82 bytestream2_put_byte(p, value_table[i]);
87 static void jpeg_put_marker(PutByteContext *pbc, int code)
89 bytestream2_put_byte(pbc, 0xff);
90 bytestream2_put_byte(pbc, code);
93 static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
94 uint32_t h, const uint8_t *qtable, int nb_qtable,
98 uint8_t *dht_size_ptr;
101 bytestream2_init_writer(&pbc, buf, size);
103 /* Convert from blocks to pixels. */
108 jpeg_put_marker(&pbc, SOI);
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);
122 jpeg_put_marker(&pbc, DRI);
123 bytestream2_put_be16(&pbc, 4);
124 bytestream2_put_be16(&pbc, dri);
128 jpeg_put_marker(&pbc, DQT);
129 bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
131 for (i = 0; i < nb_qtable; i++) {
132 bytestream2_put_byte(&pbc, i);
134 /* Each table is an array of 64 values given in zig-zag
135 * order, identical to the format used in a JFIF DQT
137 bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
141 jpeg_put_marker(&pbc, DHT);
142 dht_size_ptr = pbc.buffer;
143 bytestream2_put_be16(&pbc, 0);
146 dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
147 avpriv_mjpeg_val_dc);
148 dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
149 avpriv_mjpeg_val_dc);
150 dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
151 avpriv_mjpeg_val_ac_luminance);
152 dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
153 avpriv_mjpeg_val_ac_chrominance);
154 AV_WB16(dht_size_ptr, dht_size);
157 jpeg_put_marker(&pbc, SOF0);
158 bytestream2_put_be16(&pbc, 17); /* size */
159 bytestream2_put_byte(&pbc, 8); /* bits per component */
160 bytestream2_put_be16(&pbc, h);
161 bytestream2_put_be16(&pbc, w);
162 bytestream2_put_byte(&pbc, 3); /* number of components */
163 bytestream2_put_byte(&pbc, 1); /* component number */
164 bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
165 bytestream2_put_byte(&pbc, 0); /* matrix number */
166 bytestream2_put_byte(&pbc, 2); /* component number */
167 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
168 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
169 bytestream2_put_byte(&pbc, 3); /* component number */
170 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
171 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
174 jpeg_put_marker(&pbc, SOS);
175 bytestream2_put_be16(&pbc, 12);
176 bytestream2_put_byte(&pbc, 3);
177 bytestream2_put_byte(&pbc, 1);
178 bytestream2_put_byte(&pbc, 0);
179 bytestream2_put_byte(&pbc, 2);
180 bytestream2_put_byte(&pbc, 17);
181 bytestream2_put_byte(&pbc, 3);
182 bytestream2_put_byte(&pbc, 17);
183 bytestream2_put_byte(&pbc, 0);
184 bytestream2_put_byte(&pbc, 63);
185 bytestream2_put_byte(&pbc, 0);
187 /* Return the length in bytes of the JPEG header. */
188 return bytestream2_tell_p(&pbc);
191 static void create_default_qtables(uint8_t *qtables, uint8_t q)
196 factor = av_clip(q, 1, 99);
201 q = 200 - factor * 2;
203 for (i = 0; i < 128; i++) {
204 int val = (default_quantizers[i] * q + 50) / 100;
206 /* Limit the quantizers to 1 <= q <= 255. */
207 val = av_clip(val, 1, 255);
212 static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
213 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
214 const uint8_t *buf, int len, uint16_t seq,
217 uint8_t type, q, width, height;
218 const uint8_t *qtables = NULL;
224 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
225 return AVERROR_INVALIDDATA;
228 /* Parse the main JPEG header. */
229 off = AV_RB24(buf + 1); /* fragment byte offset */
230 type = AV_RB8(buf + 4); /* id of jpeg decoder params */
231 q = AV_RB8(buf + 5); /* quantization factor (or table id) */
232 width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
233 height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
239 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
240 return AVERROR_INVALIDDATA;
247 /* Parse the restart marker header. */
249 av_log(ctx, AV_LOG_ERROR,
250 "Unimplemented RTP/JPEG restart marker header.\n");
251 return AVERROR_PATCHWELCOME;
254 av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
255 return AVERROR_PATCHWELCOME;
258 /* Parse the quantization table header. */
260 /* Start of JPEG data packet. */
261 uint8_t new_qtables[128];
267 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
268 return AVERROR_INVALIDDATA;
271 /* The first byte is reserved for future use. */
272 precision = AV_RB8(buf + 1); /* size of coefficients */
273 qtable_len = AV_RB16(buf + 2); /* length in bytes */
278 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
280 if (qtable_len > 0) {
281 if (len < qtable_len) {
282 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
283 return AVERROR_INVALIDDATA;
289 if (jpeg->qtables_len[q - 128] &&
290 (jpeg->qtables_len[q - 128] != qtable_len ||
291 memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
292 av_log(ctx, AV_LOG_WARNING,
293 "Quantization tables for q=%d changed\n", q);
294 } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
295 memcpy(&jpeg->qtables[q - 128][0], qtables,
297 jpeg->qtables_len[q - 128] = qtable_len;
302 av_log(ctx, AV_LOG_ERROR,
303 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
304 return AVERROR_INVALIDDATA;
306 if (!jpeg->qtables_len[q - 128]) {
307 av_log(ctx, AV_LOG_ERROR,
308 "No quantization tables known for q=%d yet.\n", q);
309 return AVERROR_INVALIDDATA;
311 qtables = &jpeg->qtables[q - 128][0];
312 qtable_len = jpeg->qtables_len[q - 128];
314 } else { /* q <= 127 */
315 if (q == 0 || q > 99) {
316 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
317 return AVERROR_INVALIDDATA;
319 create_default_qtables(new_qtables, q);
320 qtables = new_qtables;
321 qtable_len = sizeof(new_qtables);
324 /* Skip the current frame in case of the end packet
325 * has been lost somewhere. */
326 ffio_free_dyn_buf(&jpeg->frame);
328 if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
330 jpeg->timestamp = *timestamp;
332 /* Generate a frame and scan headers that can be prepended to the
333 * RTP/JPEG data payload to produce a JPEG compressed image in
334 * interchange format. */
335 jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
337 qtable_len / 64, dri);
339 /* Copy JPEG header to frame buffer. */
340 avio_write(jpeg->frame, hdr, jpeg->hdr_size);
344 av_log(ctx, AV_LOG_ERROR,
345 "Received packet without a start chunk; dropping frame.\n");
346 return AVERROR(EAGAIN);
349 if (jpeg->timestamp != *timestamp) {
350 /* Skip the current frame if timestamp is incorrect.
351 * A start packet has been lost somewhere. */
352 ffio_free_dyn_buf(&jpeg->frame);
353 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
354 return AVERROR_INVALIDDATA;
357 if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
358 av_log(ctx, AV_LOG_ERROR,
359 "Missing packets; dropping frame.\n");
360 return AVERROR(EAGAIN);
363 /* Copy data to frame buffer. */
364 avio_write(jpeg->frame, buf, len);
366 if (flags & RTP_FLAG_MARKER) {
367 /* End of JPEG data packet. */
368 uint8_t buf[2] = { 0xff, EOI };
370 /* Put EOI marker. */
371 avio_write(jpeg->frame, buf, sizeof(buf));
373 /* Prepare the JPEG packet. */
374 if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
375 av_log(ctx, AV_LOG_ERROR,
376 "Error occurred when getting frame buffer.\n");
383 return AVERROR(EAGAIN);
386 RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
388 .codec_type = AVMEDIA_TYPE_VIDEO,
389 .codec_id = AV_CODEC_ID_MJPEG,
390 .priv_data_size = sizeof(PayloadContext),
391 .close = jpeg_close_context,
392 .parse_packet = jpeg_parse_packet,
393 .static_payload_id = 26,