FFmpeg
mjpegbdec.c
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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 "codec_internal.h"
31 #include "mjpeg.h"
32 #include "mjpegdec.h"
33 
34 static uint32_t read_offs(AVCodecContext *avctx, GetBitContext *gb, uint32_t size, const char *err_msg){
35  uint32_t offs= get_bits_long(gb, 32);
36  if(offs >= size){
37  av_log(avctx, AV_LOG_WARNING, err_msg, offs, size);
38  return 0;
39  }
40  return offs;
41 }
42 
43 static int mjpegb_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
44  int *got_frame, 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  s->adobe_transform = -1;
59  s->buf_size = buf_size;
60 
62  /* reset on every SOI */
63  s->restart_interval = 0;
64  s->restart_count = 0;
65  s->mjpb_skiptosod = 0;
66 
67  if ((ret = init_get_bits8(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr))) < 0)
68  return ret;
69 
70  skip_bits(&hgb, 32); /* reserved zeros */
71 
72  if (get_bits_long(&hgb, 32) != MKBETAG('m','j','p','g')) {
73  av_log(avctx, AV_LOG_WARNING, "not mjpeg-b (bad fourcc)\n");
74  return AVERROR_INVALIDDATA;
75  }
76 
77  field_size = get_bits_long(&hgb, 32); /* field size */
78  av_log(avctx, AV_LOG_DEBUG, "field size: 0x%"PRIx32"\n", field_size);
79  skip_bits(&hgb, 32); /* padded field size */
80  second_field_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "second_field_offs is %d and size is %d\n");
81  av_log(avctx, AV_LOG_DEBUG, "second field offs: 0x%"PRIx32"\n",
82  second_field_offs);
83 
84  dqt_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "dqt is %d and size is %d\n");
85  av_log(avctx, AV_LOG_DEBUG, "dqt offs: 0x%"PRIx32"\n", dqt_offs);
86  if (dqt_offs) {
87  init_get_bits(&s->gb, buf_ptr+dqt_offs, (buf_end - (buf_ptr+dqt_offs))*8);
88  s->start_code = DQT;
90  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
91  return ret;
92  }
93 
94  dht_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "dht is %d and size is %d\n");
95  av_log(avctx, AV_LOG_DEBUG, "dht offs: 0x%"PRIx32"\n", dht_offs);
96  if (dht_offs) {
97  init_get_bits(&s->gb, buf_ptr+dht_offs, (buf_end - (buf_ptr+dht_offs))*8);
98  s->start_code = DHT;
100  }
101 
102  sof_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sof is %d and size is %d\n");
103  av_log(avctx, AV_LOG_DEBUG, "sof offs: 0x%"PRIx32"\n", sof_offs);
104  if (sof_offs) {
105  init_get_bits(&s->gb, buf_ptr+sof_offs, (buf_end - (buf_ptr+sof_offs))*8);
106  s->start_code = SOF0;
107  if ((ret = ff_mjpeg_decode_sof(s)) < 0)
108  return ret;
109  }
110 
111  sos_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sos is %d and size is %d\n");
112  av_log(avctx, AV_LOG_DEBUG, "sos offs: 0x%"PRIx32"\n", sos_offs);
113  sod_offs = read_offs(avctx, &hgb, buf_end - buf_ptr, "sof is %d and size is %d\n");
114  av_log(avctx, AV_LOG_DEBUG, "sod offs: 0x%"PRIx32"\n", sod_offs);
115  if (sos_offs) {
116  init_get_bits(&s->gb, buf_ptr + sos_offs,
117  8 * FFMIN(field_size, buf_end - buf_ptr - sos_offs));
118  s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
119  s->start_code = SOS;
120  if (avctx->skip_frame == AVDISCARD_ALL) {
121  skip_bits(&s->gb, get_bits_left(&s->gb));
122  } else {
124  if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
125  return ret;
126  }
127  }
128 
129  if (s->interlaced) {
130  s->bottom_field ^= 1;
131  /* if not bottom field, do not output image yet */
132  if (s->bottom_field != s->interlace_polarity && second_field_offs) {
133  buf_ptr = buf + second_field_offs;
134  goto read_header;
135  }
136  }
137 
138  //XXX FIXME factorize, this looks very similar to the EOI code
139 
140  if(!s->got_picture) {
141  av_log(avctx, AV_LOG_WARNING, "no picture\n");
142  return buf_size;
143  }
144  av_frame_move_ref(rframe, s->picture_ptr);
145  s->got_picture = 0;
146  if (avctx->skip_frame == AVDISCARD_ALL)
147  return buf_size;
148  *got_frame = 1;
149 
150  if (!s->lossless && avctx->debug & FF_DEBUG_QP) {
151  av_log(avctx, AV_LOG_DEBUG, "QP: %d\n",
152  FFMAX3(s->qscale[0], s->qscale[1], s->qscale[2]));
153  }
154 
155  return buf_size;
156 }
157 
159  .p.name = "mjpegb",
160  CODEC_LONG_NAME("Apple MJPEG-B"),
161  .p.type = AVMEDIA_TYPE_VIDEO,
162  .p.id = AV_CODEC_ID_MJPEGB,
163  .priv_data_size = sizeof(MJpegDecodeContext),
165  .close = ff_mjpeg_decode_end,
167  .p.capabilities = AV_CODEC_CAP_DR1,
168  .p.max_lowres = 3,
169  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
170 };
171 
173  .p.name = "media100",
174  CODEC_LONG_NAME("Media 100"),
175  .p.type = AVMEDIA_TYPE_VIDEO,
176  .p.id = AV_CODEC_ID_MEDIA100,
177  .priv_data_size = sizeof(MJpegDecodeContext),
179  .close = ff_mjpeg_decode_end,
181  .p.capabilities = AV_CODEC_CAP_DR1,
182  .p.max_lowres = 3,
183  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
184  .bsfs = "media100_to_mjpegb",
185 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
mjpeg.h
AV_EF_EXPLODE
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: defs.h:51
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:694
SOS
@ SOS
Definition: mjpeg.h:72
SOF0
@ SOF0
Definition: mjpeg.h:39
AVCodecContext::err_recognition
int err_recognition
Error recognition; may misdetect some more or less valid parts as errors.
Definition: avcodec.h:1412
get_bits_long
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:421
mjpegdec.h
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacket::data
uint8_t * data
Definition: packet.h:491
FFCodec
Definition: codec_internal.h:127
AV_CODEC_ID_MEDIA100
@ AV_CODEC_ID_MEDIA100
Definition: codec_id.h:321
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:514
skip_bits
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:381
ff_mjpeg_decode_dht
int ff_mjpeg_decode_dht(MJpegDecodeContext *s)
Definition: mjpegdec.c:241
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
ff_mjpeg_decode_init
av_cold int ff_mjpeg_decode_init(AVCodecContext *avctx)
Definition: mjpegdec.c:124
AVCodecContext::skip_frame
enum AVDiscard skip_frame
Skip decoding for selected frames.
Definition: avcodec.h:1766
GetBitContext
Definition: get_bits.h:108
ff_media100_decoder
const FFCodec ff_media100_decoder
Definition: mjpegbdec.c:172
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:545
ff_mjpegb_decoder
const FFCodec ff_mjpegb_decoder
Definition: mjpegbdec.c:158
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:306
s
#define s(width, name)
Definition: cbs_vp9.c:198
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:365
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
ff_mjpeg_decode_end
av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)
Definition: mjpegdec.c:2934
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
AVDISCARD_ALL
@ AVDISCARD_ALL
discard all
Definition: defs.h:219
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
NULL
#define NULL
Definition: coverity.c:32
read_offs
static uint32_t read_offs(AVCodecContext *avctx, GetBitContext *gb, uint32_t size, const char *err_msg)
Definition: mjpegbdec.c:34
ff_mjpeg_decode_dqt
int ff_mjpeg_decode_dqt(MJpegDecodeContext *s)
Definition: mjpegdec.c:198
MJpegDecodeContext
Definition: mjpegdec.h:54
mjpegb_decode_frame
static int mjpegb_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)
Definition: mjpegbdec.c:43
AV_CODEC_ID_MJPEGB
@ AV_CODEC_ID_MJPEGB
Definition: codec_id.h:60
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:492
codec_internal.h
ff_mjpeg_decode_sos
int ff_mjpeg_decode_sos(MJpegDecodeContext *s, const uint8_t *mb_bitmask, int mb_bitmask_size, const AVFrame *reference)
Definition: mjpegdec.c:1668
size
int size
Definition: twinvq_data.h:10344
MKBETAG
#define MKBETAG(a, b, c, d)
Definition: macros.h:56
DQT
@ DQT
Definition: mjpeg.h:73
show_bits
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition: get_bits.h:371
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
av_frame_move_ref
void av_frame_move_ref(AVFrame *dst, AVFrame *src)
Move everything contained in src to dst and reset src.
Definition: frame.c:649
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
DHT
@ DHT
Definition: mjpeg.h:56
avcodec.h
ret
ret
Definition: filter_design.txt:187
FF_DEBUG_QP
#define FF_DEBUG_QP
Definition: avcodec.h:1393
AVCodecContext
main external API structure.
Definition: avcodec.h:441
AVCodecContext::debug
int debug
debug
Definition: avcodec.h:1388
ff_mjpeg_decode_sof
int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
Definition: mjpegdec.c:302
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:468
AVPacket
This structure stores compressed data.
Definition: packet.h:468
FFMAX3
#define FFMAX3(a, b, c)
Definition: macros.h:48
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61