2 * RTP JPEG-compressed Video Depacketizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
5 * This file is part of Libav.
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.
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.
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
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_free_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)
97 uint8_t *dht_size_ptr;
100 bytestream2_init_writer(&pbc, buf, size);
102 /* Convert from blocks to pixels. */
107 jpeg_put_marker(&pbc, SOI);
110 jpeg_put_marker(&pbc, APP0);
111 bytestream2_put_be16(&pbc, 16);
112 bytestream2_put_buffer(&pbc, "JFIF", 5);
113 bytestream2_put_be16(&pbc, 0x0201);
114 bytestream2_put_byte(&pbc, 0);
115 bytestream2_put_be16(&pbc, 1);
116 bytestream2_put_be16(&pbc, 1);
117 bytestream2_put_byte(&pbc, 0);
118 bytestream2_put_byte(&pbc, 0);
121 jpeg_put_marker(&pbc, DQT);
122 bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
124 for (i = 0; i < nb_qtable; i++) {
125 bytestream2_put_byte(&pbc, i);
127 /* Each table is an array of 64 values given in zig-zag
128 * order, identical to the format used in a JFIF DQT
130 bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
134 jpeg_put_marker(&pbc, DHT);
135 dht_size_ptr = pbc.buffer;
136 bytestream2_put_be16(&pbc, 0);
139 dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
140 avpriv_mjpeg_val_dc);
141 dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
142 avpriv_mjpeg_val_dc);
143 dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
144 avpriv_mjpeg_val_ac_luminance);
145 dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
146 avpriv_mjpeg_val_ac_chrominance);
147 AV_WB16(dht_size_ptr, dht_size);
150 jpeg_put_marker(&pbc, SOF0);
151 bytestream2_put_be16(&pbc, 17); /* size */
152 bytestream2_put_byte(&pbc, 8); /* bits per component */
153 bytestream2_put_be16(&pbc, h);
154 bytestream2_put_be16(&pbc, w);
155 bytestream2_put_byte(&pbc, 3); /* number of components */
156 bytestream2_put_byte(&pbc, 1); /* component number */
157 bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
158 bytestream2_put_byte(&pbc, 0); /* matrix number */
159 bytestream2_put_byte(&pbc, 2); /* component number */
160 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
161 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
162 bytestream2_put_byte(&pbc, 3); /* component number */
163 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
164 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
167 jpeg_put_marker(&pbc, SOS);
168 bytestream2_put_be16(&pbc, 12);
169 bytestream2_put_byte(&pbc, 3);
170 bytestream2_put_byte(&pbc, 1);
171 bytestream2_put_byte(&pbc, 0);
172 bytestream2_put_byte(&pbc, 2);
173 bytestream2_put_byte(&pbc, 17);
174 bytestream2_put_byte(&pbc, 3);
175 bytestream2_put_byte(&pbc, 17);
176 bytestream2_put_byte(&pbc, 0);
177 bytestream2_put_byte(&pbc, 63);
178 bytestream2_put_byte(&pbc, 0);
180 /* Return the length in bytes of the JPEG header. */
181 return bytestream2_tell_p(&pbc);
184 static void create_default_qtables(uint8_t *qtables, uint8_t q)
189 factor = av_clip(q, 1, 99);
194 q = 200 - factor * 2;
196 for (i = 0; i < 128; i++) {
197 int val = (default_quantizers[i] * q + 50) / 100;
199 /* Limit the quantizers to 1 <= q <= 255. */
200 val = av_clip(val, 1, 255);
205 static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
206 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
207 const uint8_t *buf, int len, uint16_t seq,
210 uint8_t type, q, width, height;
211 const uint8_t *qtables = NULL;
217 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
218 return AVERROR_INVALIDDATA;
221 /* Parse the main JPEG header. */
222 off = AV_RB24(buf + 1); /* fragment byte offset */
223 type = AV_RB8(buf + 4); /* id of jpeg decoder params */
224 q = AV_RB8(buf + 5); /* quantization factor (or table id) */
225 width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
226 height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
230 /* Parse the restart marker header. */
232 av_log(ctx, AV_LOG_ERROR,
233 "Unimplemented RTP/JPEG restart marker header.\n");
234 return AVERROR_PATCHWELCOME;
237 av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
238 return AVERROR_PATCHWELCOME;
241 /* Parse the quantization table header. */
243 /* Start of JPEG data packet. */
244 uint8_t new_qtables[128];
250 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
251 return AVERROR_INVALIDDATA;
254 /* The first byte is reserved for future use. */
255 precision = AV_RB8(buf + 1); /* size of coefficients */
256 qtable_len = AV_RB16(buf + 2); /* length in bytes */
261 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
263 if (qtable_len > 0) {
264 if (len < qtable_len) {
265 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
266 return AVERROR_INVALIDDATA;
272 if (jpeg->qtables_len[q - 128] &&
273 (jpeg->qtables_len[q - 128] != qtable_len ||
274 memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
275 av_log(ctx, AV_LOG_WARNING,
276 "Quantization tables for q=%d changed\n", q);
277 } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
278 memcpy(&jpeg->qtables[q - 128][0], qtables,
280 jpeg->qtables_len[q - 128] = qtable_len;
285 av_log(ctx, AV_LOG_ERROR,
286 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
287 return AVERROR_INVALIDDATA;
289 if (!jpeg->qtables_len[q - 128]) {
290 av_log(ctx, AV_LOG_ERROR,
291 "No quantization tables known for q=%d yet.\n", q);
292 return AVERROR_INVALIDDATA;
294 qtables = &jpeg->qtables[q - 128][0];
295 qtable_len = jpeg->qtables_len[q - 128];
297 } else { /* q <= 127 */
298 if (q == 0 || q > 99) {
299 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
300 return AVERROR_INVALIDDATA;
302 create_default_qtables(new_qtables, q);
303 qtables = new_qtables;
304 qtable_len = sizeof(new_qtables);
307 /* Skip the current frame in case of the end packet
308 * has been lost somewhere. */
309 ffio_free_dyn_buf(&jpeg->frame);
311 if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
313 jpeg->timestamp = *timestamp;
315 /* Generate a frame and scan headers that can be prepended to the
316 * RTP/JPEG data payload to produce a JPEG compressed image in
317 * interchange format. */
318 jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
322 /* Copy JPEG header to frame buffer. */
323 avio_write(jpeg->frame, hdr, jpeg->hdr_size);
327 av_log(ctx, AV_LOG_ERROR,
328 "Received packet without a start chunk; dropping frame.\n");
329 return AVERROR(EAGAIN);
332 if (jpeg->timestamp != *timestamp) {
333 /* Skip the current frame if timestamp is incorrect.
334 * A start packet has been lost somewhere. */
335 ffio_free_dyn_buf(&jpeg->frame);
336 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
337 return AVERROR_INVALIDDATA;
340 if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
341 av_log(ctx, AV_LOG_ERROR,
342 "Missing packets; dropping frame.\n");
343 return AVERROR(EAGAIN);
346 /* Copy data to frame buffer. */
347 avio_write(jpeg->frame, buf, len);
349 if (flags & RTP_FLAG_MARKER) {
350 /* End of JPEG data packet. */
351 uint8_t buf[2] = { 0xff, EOI };
353 /* Put EOI marker. */
354 avio_write(jpeg->frame, buf, sizeof(buf));
356 /* Prepare the JPEG packet. */
357 if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
358 av_log(ctx, AV_LOG_ERROR,
359 "Error occurred when getting frame buffer.\n");
366 return AVERROR(EAGAIN);
369 RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
371 .codec_type = AVMEDIA_TYPE_VIDEO,
372 .codec_id = AV_CODEC_ID_MJPEG,
373 .priv_data_size = sizeof(PayloadContext),
374 .free = jpeg_free_context,
375 .parse_packet = jpeg_parse_packet,
376 .static_payload_id = 26,