Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / mjpegbdec.c
CommitLineData
2ba45a60
DM
1/*
2 * Apple MJPEG-B decoder
3 * Copyright (c) 2002 Alex Beregszaszi
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 * @file
24 * Apple MJPEG-B decoder.
25 */
26
27#include <inttypes.h>
28
29#include "avcodec.h"
30#include "mjpeg.h"
31#include "mjpegdec.h"
32
33static uint32_t read_offs(AVCodecContext *avctx, GetBitContext *gb, uint32_t size, const char *err_msg){
34 uint32_t offs= get_bits_long(gb, 32);
35 if(offs >= size){
36 av_log(avctx, AV_LOG_WARNING, err_msg, offs, size);
37 return 0;
38 }
39 return offs;
40}
41
42static int mjpegb_decode_frame(AVCodecContext *avctx,
43 void *data, int *got_frame,
44 AVPacket *avpkt)
45{
46 const uint8_t *buf = avpkt->data;
47 int buf_size = avpkt->size;
48 MJpegDecodeContext *s = avctx->priv_data;
49 const uint8_t *buf_end, *buf_ptr;
50 GetBitContext hgb; /* for the header */
51 uint32_t dqt_offs, dht_offs, sof_offs, sos_offs, second_field_offs;
52 uint32_t field_size, sod_offs;
53 int ret;
54
55 buf_ptr = buf;
56 buf_end = buf + buf_size;
57 s->got_picture = 0;
58
59read_header:
60 /* reset on every SOI */
61 s->restart_interval = 0;
62 s->restart_count = 0;
63 s->mjpb_skiptosod = 0;
64
65 if (buf_end - buf_ptr >= 1 << 28)
66 return AVERROR_INVALIDDATA;
67
68 init_get_bits(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr)*8);
69
70 skip_bits(&hgb, 32); /* reserved zeros */
71
72 if (get_bits_long(&hgb, 32) != MKBETAG('m','j','p','g'))
73 {
74 av_log(avctx, AV_LOG_WARNING, "not mjpeg-b (bad fourcc)\n");
75 return AVERROR_INVALIDDATA;
76 }
77
78 field_size = get_bits_long(&hgb, 32); /* field size */
79 av_log(avctx, AV_LOG_DEBUG, "field size: 0x%"PRIx32"\n", field_size);
80 skip_bits(&hgb, 32); /* padded field size */
81 second_field_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "second_field_offs is %d and size is %d\n");
82 av_log(avctx, AV_LOG_DEBUG, "second field offs: 0x%"PRIx32"\n",
83 second_field_offs);
84
85 dqt_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "dqt is %d and size is %d\n");
86 av_log(avctx, AV_LOG_DEBUG, "dqt offs: 0x%"PRIx32"\n", dqt_offs);
87 if (dqt_offs)
88 {
89 init_get_bits(&s->gb, buf_ptr+dqt_offs, (buf_end - (buf_ptr+dqt_offs))*8);
90 s->start_code = DQT;
91 if (ff_mjpeg_decode_dqt(s) < 0 &&
92 (avctx->err_recognition & AV_EF_EXPLODE))
93 return AVERROR_INVALIDDATA;
94 }
95
96 dht_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "dht is %d and size is %d\n");
97 av_log(avctx, AV_LOG_DEBUG, "dht offs: 0x%"PRIx32"\n", dht_offs);
98 if (dht_offs)
99 {
100 init_get_bits(&s->gb, buf_ptr+dht_offs, (buf_end - (buf_ptr+dht_offs))*8);
101 s->start_code = DHT;
102 ff_mjpeg_decode_dht(s);
103 }
104
105 sof_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sof is %d and size is %d\n");
106 av_log(avctx, AV_LOG_DEBUG, "sof offs: 0x%"PRIx32"\n", sof_offs);
107 if (sof_offs)
108 {
109 init_get_bits(&s->gb, buf_ptr+sof_offs, (buf_end - (buf_ptr+sof_offs))*8);
110 s->start_code = SOF0;
111 if (ff_mjpeg_decode_sof(s) < 0)
112 return -1;
113 }
114
115 sos_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sos is %d and size is %d\n");
116 av_log(avctx, AV_LOG_DEBUG, "sos offs: 0x%"PRIx32"\n", sos_offs);
117 sod_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sof is %d and size is %d\n");
118 av_log(avctx, AV_LOG_DEBUG, "sod offs: 0x%"PRIx32"\n", sod_offs);
119 if (sos_offs)
120 {
121 init_get_bits(&s->gb, buf_ptr + sos_offs,
122 8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs));
123 s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
124 s->start_code = SOS;
125 if (ff_mjpeg_decode_sos(s, NULL, 0, NULL) < 0 &&
126 (avctx->err_recognition & AV_EF_EXPLODE))
127 return AVERROR_INVALIDDATA;
128 }
129
130 if (s->interlaced) {
131 s->bottom_field ^= 1;
132 /* if not bottom field, do not output image yet */
133 if (s->bottom_field != s->interlace_polarity && second_field_offs)
134 {
135 buf_ptr = buf + second_field_offs;
136 goto read_header;
137 }
138 }
139
140 //XXX FIXME factorize, this looks very similar to the EOI code
141
142 if(!s->got_picture) {
143 av_log(avctx, AV_LOG_WARNING, "no picture\n");
144 return buf_size;
145 }
146
147 if ((ret = av_frame_ref(data, s->picture_ptr)) < 0)
148 return ret;
149 *got_frame = 1;
150
151 if (!s->lossless && avctx->debug & FF_DEBUG_QP) {
152 av_log(avctx, AV_LOG_DEBUG, "QP: %d\n",
153 FFMAX3(s->qscale[0], s->qscale[1], s->qscale[2]));
154 }
155
156 return buf_size;
157}
158
159AVCodec ff_mjpegb_decoder = {
160 .name = "mjpegb",
161 .long_name = NULL_IF_CONFIG_SMALL("Apple MJPEG-B"),
162 .type = AVMEDIA_TYPE_VIDEO,
163 .id = AV_CODEC_ID_MJPEGB,
164 .priv_data_size = sizeof(MJpegDecodeContext),
165 .init = ff_mjpeg_decode_init,
166 .close = ff_mjpeg_decode_end,
167 .decode = mjpegb_decode_frame,
168 .capabilities = CODEC_CAP_DR1,
169 .max_lowres = 3,
170};