path: root/libavcodec/mjpeg2jpeg_bsf.c (plain)
blob: 6f02bc033caaa073a9d2f7ebcdd589cdfda19122

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/mem.h"
31	#include "libavutil/intreadwrite.h"
32
33	#include "avcodec.h"
34	#include "bsf.h"
35	#include "jpegtables.h"
36	#include "mjpeg.h"
37
38	static const uint8_t jpeg_header[] = {
39	0xff, 0xd8, // SOI
40	0xff, 0xe0, // APP0
41	0x00, 0x10, // APP0 header size (including
42	// this field, but excluding preceding)
43	0x4a, 0x46, 0x49, 0x46, 0x00, // ID string 'JFIF\0'
44	0x01, 0x01, // version
45	0x00, // bits per type
46	0x00, 0x00, // X density
47	0x00, 0x00, // Y density
48	0x00, // X thumbnail size
49	0x00, // Y thumbnail size
50	};
51
52	static const int dht_segment_size = 420;
53	static const uint8_t dht_segment_head[] = { 0xFF, 0xC4, 0x01, 0xA2, 0x00 };
54	static const uint8_t dht_segment_frag[] = {
55	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
56	0x0a, 0x0b, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
57	0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
58	};
59
60	static uint8_t *append(uint8_t *buf, const uint8_t *src, int size)
61	{
62	memcpy(buf, src, size);
63	return buf + size;
64	}
65
66	static uint8_t *append_dht_segment(uint8_t *buf)
67	{
68	buf = append(buf, dht_segment_head, sizeof(dht_segment_head));
69	buf = append(buf, avpriv_mjpeg_bits_dc_luminance + 1, 16);
70	buf = append(buf, dht_segment_frag, sizeof(dht_segment_frag));
71	buf = append(buf, avpriv_mjpeg_val_dc, 12);
72	*(buf++) = 0x10;
73	buf = append(buf, avpriv_mjpeg_bits_ac_luminance + 1, 16);
74	buf = append(buf, avpriv_mjpeg_val_ac_luminance, 162);
75	*(buf++) = 0x11;
76	buf = append(buf, avpriv_mjpeg_bits_ac_chrominance + 1, 16);
77	buf = append(buf, avpriv_mjpeg_val_ac_chrominance, 162);
78	return buf;
79	}
80
81	static int mjpeg2jpeg_filter(AVBSFContext *ctx, AVPacket *out)
82	{
83	AVPacket *in;
84	int ret = 0;
85	int input_skip, output_size;
86	uint8_t *output;
87
88	ret = ff_bsf_get_packet(ctx, &in);
89	if (ret < 0)
90	return ret;
91
92	if (in->size < 12) {
93	av_log(ctx, AV_LOG_ERROR, "input is truncated\n");
94	ret = AVERROR_INVALIDDATA;
95	goto fail;
96	}
97	if (AV_RB16(in->data) != 0xffd8) {
98	av_log(ctx, AV_LOG_ERROR, "input is not MJPEG\n");
99	ret = AVERROR_INVALIDDATA;
100	goto fail;
101	}
102	if (in->data[2] == 0xff && in->data[3] == APP0) {
103	input_skip = (in->data[4] << 8) + in->data[5] + 4;
104	} else {
105	input_skip = 2;
106	}
107	if (in->size < input_skip) {
108	av_log(ctx, AV_LOG_ERROR, "input is truncated\n");
109	ret = AVERROR_INVALIDDATA;
110	goto fail;
111	}
112	output_size = in->size - input_skip +
113	sizeof(jpeg_header) + dht_segment_size;
114	ret = av_new_packet(out, output_size);
115	if (ret < 0)
116	goto fail;
117
118	output = out->data;
119
120	output = append(output, jpeg_header, sizeof(jpeg_header));
121	output = append_dht_segment(output);
122	output = append(output, in->data + input_skip, in->size - input_skip);
123
124	ret = av_packet_copy_props(out, in);
125	if (ret < 0)
126	goto fail;
127
128	fail:
129	if (ret < 0)
130	av_packet_unref(out);
131	av_packet_free(&in);
132	return ret;
133	}
134
135	static const enum AVCodecID codec_ids[] = {
136	AV_CODEC_ID_MJPEG, AV_CODEC_ID_NONE,
137	};
138
139	const AVBitStreamFilter ff_mjpeg2jpeg_bsf = {
140	.name = "mjpeg2jpeg",
141	.filter = mjpeg2jpeg_filter,
142	.codec_ids = codec_ids,
143	};
144