1/*
2 * MJPEG/AVI1 to JPEG/JFIF bitstream format filter
3 * Copyright (c) 2010 Adrian Daerr and Nicolas George
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/*
23 * Adapted from mjpeg2jpeg.c, with original copyright:
24 * Paris 2010 Adrian Daerr, public domain
25 */
26
27#include <string.h>
28
29#include "libavutil/error.h"
30#include "libavutil/intreadwrite.h"
31
32#include "bsf.h"
33#include "bsf_internal.h"
34#include "jpegtables.h"
35#include "mjpeg.h"
36
37static const uint8_t jpeg_header[] = {
38    0xff, 0xd8,                     // SOI
39    0xff, 0xe0,                     // APP0
40    0x00, 0x10,                     // APP0 header size (including
41                                    // this field, but excluding preceding)
42    0x4a, 0x46, 0x49, 0x46, 0x00,   // ID string 'JFIF\0'
43    0x01, 0x01,                     // version
44    0x00,                           // bits per type
45    0x00, 0x00,                     // X density
46    0x00, 0x00,                     // Y density
47    0x00,                           // X thumbnail size
48    0x00,                           // Y thumbnail size
49};
50
51static const int dht_segment_size = 420;
52static const uint8_t dht_segment_head[] = { 0xFF, 0xC4, 0x01, 0xA2, 0x00 };
53static const uint8_t dht_segment_frag[] = {
54    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
55    0x0a, 0x0b, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
56    0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
57};
58
59static uint8_t *append(uint8_t *buf, const uint8_t *src, int size)
60{
61    memcpy(buf, src, size);
62    return buf + size;
63}
64
65static uint8_t *append_dht_segment(uint8_t *buf)
66{
67    buf = append(buf, dht_segment_head, sizeof(dht_segment_head));
68    buf = append(buf, ff_mjpeg_bits_dc_luminance + 1, 16);
69    buf = append(buf, dht_segment_frag, sizeof(dht_segment_frag));
70    buf = append(buf, ff_mjpeg_val_dc, 12);
71    *(buf++) = 0x10;
72    buf = append(buf, ff_mjpeg_bits_ac_luminance + 1, 16);
73    buf = append(buf, ff_mjpeg_val_ac_luminance, 162);
74    *(buf++) = 0x11;
75    buf = append(buf, ff_mjpeg_bits_ac_chrominance + 1, 16);
76    buf = append(buf, ff_mjpeg_val_ac_chrominance, 162);
77    return buf;
78}
79
80static int mjpeg2jpeg_filter(AVBSFContext *ctx, AVPacket *out)
81{
82    AVPacket *in;
83    int ret = 0;
84    int input_skip, output_size;
85    uint8_t *output;
86
87    ret = ff_bsf_get_packet(ctx, &in);
88    if (ret < 0)
89        return ret;
90
91    if (in->size < 12) {
92        av_log(ctx, AV_LOG_ERROR, "input is truncated\n");
93        ret = AVERROR_INVALIDDATA;
94        goto fail;
95    }
96    if (AV_RB16(in->data) != 0xffd8) {
97        av_log(ctx, AV_LOG_ERROR, "input is not MJPEG\n");
98        ret = AVERROR_INVALIDDATA;
99        goto fail;
100    }
101    if (in->data[2] == 0xff && in->data[3] == APP0) {
102        input_skip = (in->data[4] << 8) + in->data[5] + 4;
103    } else {
104        input_skip = 2;
105    }
106    if (in->size < input_skip) {
107        av_log(ctx, AV_LOG_ERROR, "input is truncated\n");
108        ret = AVERROR_INVALIDDATA;
109        goto fail;
110    }
111    output_size = in->size - input_skip +
112                  sizeof(jpeg_header) + dht_segment_size;
113    ret = av_new_packet(out, output_size);
114    if (ret < 0)
115        goto fail;
116
117    output = out->data;
118
119    output = append(output, jpeg_header, sizeof(jpeg_header));
120    output = append_dht_segment(output);
121    output = append(output, in->data + input_skip, in->size - input_skip);
122
123    ret = av_packet_copy_props(out, in);
124    if (ret < 0)
125        goto fail;
126
127fail:
128    if (ret < 0)
129        av_packet_unref(out);
130    av_packet_free(&in);
131    return ret;
132}
133
134static const enum AVCodecID codec_ids[] = {
135    AV_CODEC_ID_MJPEG, AV_CODEC_ID_NONE,
136};
137
138const FFBitStreamFilter ff_mjpeg2jpeg_bsf = {
139    .p.name         = "mjpeg2jpeg",
140    .p.codec_ids    = codec_ids,
141    .filter         = mjpeg2jpeg_filter,
142};
143