2 * MJPEG/AVI1 to JPEG/JFIF bitstream format filter
3 * Copyright (c) 2010 Adrian Daerr and Nicolas George
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 * Adapted from mjpeg2jpeg.c, with original copyright:
24 * Paris 2010 Adrian Daerr, public domain
29 #include "libavutil/error.h"
30 #include "libavutil/mem.h"
34 #include "jpegtables.h"
36 static const uint8_t jpeg_header[] = {
39 0x00, 0x10, // APP0 header size (including
40 // this field, but excluding preceding)
41 0x4a, 0x46, 0x49, 0x46, 0x00, // ID string 'JFIF\0'
42 0x01, 0x01, // version
43 0x00, // bits per type
44 0x00, 0x00, // X density
45 0x00, 0x00, // Y density
46 0x00, // X thumbnail size
47 0x00, // Y thumbnail size
50 static const int dht_segment_size = 420;
51 static const uint8_t dht_segment_head[] = { 0xFF, 0xC4, 0x01, 0xA2, 0x00 };
52 static const uint8_t dht_segment_frag[] = {
53 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
54 0x0a, 0x0b, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
55 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
58 static uint8_t *append(uint8_t *buf, const uint8_t *src, int size)
60 memcpy(buf, src, size);
64 static uint8_t *append_dht_segment(uint8_t *buf)
66 buf = append(buf, dht_segment_head, sizeof(dht_segment_head));
67 buf = append(buf, avpriv_mjpeg_bits_dc_luminance + 1, 16);
68 buf = append(buf, dht_segment_frag, sizeof(dht_segment_frag));
69 buf = append(buf, avpriv_mjpeg_val_dc, 12);
71 buf = append(buf, avpriv_mjpeg_bits_ac_luminance + 1, 16);
72 buf = append(buf, avpriv_mjpeg_val_ac_luminance, 162);
74 buf = append(buf, avpriv_mjpeg_bits_ac_chrominance + 1, 16);
75 buf = append(buf, avpriv_mjpeg_val_ac_chrominance, 162);
79 static int mjpeg2jpeg_filter(AVBSFContext *ctx, AVPacket *out)
83 int input_skip, output_size;
86 ret = ff_bsf_get_packet(ctx, &in);
89 av_log(ctx, AV_LOG_ERROR, "input is truncated\n");
90 ret = AVERROR_INVALIDDATA;
93 if (memcmp("AVI1", in->data + 6, 4)) {
94 av_log(ctx, AV_LOG_ERROR, "input is not MJPEG/AVI1\n");
95 ret = AVERROR_INVALIDDATA;
99 input_skip = (in->data[4] << 8) + in->data[5] + 4;
100 if (in->size < input_skip) {
101 av_log(ctx, AV_LOG_ERROR, "input is truncated\n");
102 ret = AVERROR_INVALIDDATA;
105 output_size = in->size - input_skip +
106 sizeof(jpeg_header) + dht_segment_size;
107 ret = av_new_packet(out, output_size);
113 output = append(output, jpeg_header, sizeof(jpeg_header));
114 output = append_dht_segment(output);
115 output = append(output, in->data + input_skip, in->size - input_skip);
117 ret = av_packet_copy_props(out, in);
123 av_packet_unref(out);
128 const AVBitStreamFilter ff_mjpeg2jpeg_bsf = {
129 .name = "mjpeg2jpeg",
130 .filter = mjpeg2jpeg_filter,