FFmpeg
cscd.c
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1 /*
2  * CamStudio decoder
3  * Copyright (c) 2006 Reimar Doeffinger
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 #include <stdio.h>
22 #include <stdlib.h>
23 
24 #include "avcodec.h"
25 #include "internal.h"
26 #include "libavutil/common.h"
27 
28 #if CONFIG_ZLIB
29 #include <zlib.h>
30 #endif
31 #include "libavutil/lzo.h"
32 
33 typedef struct CamStudioContext {
36  unsigned int decomp_size;
37  unsigned char* decomp_buf;
39 
40 static void copy_frame_default(AVFrame *f, const uint8_t *src,
41  int linelen, int height)
42 {
43  int i, src_stride = FFALIGN(linelen, 4);
44  uint8_t *dst = f->data[0];
45  dst += (height - 1) * f->linesize[0];
46  for (i = height; i; i--) {
47  memcpy(dst, src, linelen);
48  src += src_stride;
49  dst -= f->linesize[0];
50  }
51 }
52 
53 static void add_frame_default(AVFrame *f, const uint8_t *src,
54  int linelen, int height)
55 {
56  int i, j, src_stride = FFALIGN(linelen, 4);
57  uint8_t *dst = f->data[0];
58  dst += (height - 1) * f->linesize[0];
59  for (i = height; i; i--) {
60  for (j = linelen; j; j--)
61  *dst++ += *src++;
62  src += src_stride - linelen;
63  dst -= f->linesize[0] + linelen;
64  }
65 }
66 
67 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
68  AVPacket *avpkt)
69 {
70  const uint8_t *buf = avpkt->data;
71  int buf_size = avpkt->size;
72  CamStudioContext *c = avctx->priv_data;
73  int ret;
74 
75  if (buf_size < 2) {
76  av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
77  return AVERROR_INVALIDDATA;
78  }
79 
80  if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
81  return ret;
82 
83  // decompress data
84  switch ((buf[0] >> 1) & 7) {
85  case 0: { // lzo compression
86  int outlen = c->decomp_size, inlen = buf_size - 2;
87  if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen) || outlen) {
88  av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
89  return AVERROR_INVALIDDATA;
90  }
91  break;
92  }
93  case 1: { // zlib compression
94 #if CONFIG_ZLIB
95  unsigned long dlen = c->decomp_size;
96  if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK || dlen != c->decomp_size) {
97  av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
98  return AVERROR_INVALIDDATA;
99  }
100  break;
101 #else
102  av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
103  return AVERROR(ENOSYS);
104 #endif
105  }
106  default:
107  av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
108  return AVERROR_INVALIDDATA;
109  }
110 
111  // flip upside down, add difference frame
112  if (buf[0] & 1) { // keyframe
113  c->pic->pict_type = AV_PICTURE_TYPE_I;
114  c->pic->key_frame = 1;
115  copy_frame_default(c->pic, c->decomp_buf,
116  c->linelen, c->height);
117  } else {
118  c->pic->pict_type = AV_PICTURE_TYPE_P;
119  c->pic->key_frame = 0;
120  add_frame_default(c->pic, c->decomp_buf,
121  c->linelen, c->height);
122  }
123 
124  *got_frame = 1;
125  if ((ret = av_frame_ref(data, c->pic)) < 0)
126  return ret;
127 
128  return buf_size;
129 }
130 
132 {
133  CamStudioContext *c = avctx->priv_data;
134  int stride;
135  switch (avctx->bits_per_coded_sample) {
136  case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555LE; break;
137  case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
138  case 32: avctx->pix_fmt = AV_PIX_FMT_BGR0; break;
139  default:
140  av_log(avctx, AV_LOG_ERROR,
141  "CamStudio codec error: invalid depth %i bpp\n",
142  avctx->bits_per_coded_sample);
143  return AVERROR_INVALIDDATA;
144  }
145  c->bpp = avctx->bits_per_coded_sample;
146  c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
147  c->height = avctx->height;
148  stride = FFALIGN(c->linelen, 4);
149  c->decomp_size = c->height * stride;
150  c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
151  if (!c->decomp_buf) {
152  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
153  return AVERROR(ENOMEM);
154  }
155  c->pic = av_frame_alloc();
156  if (!c->pic)
157  return AVERROR(ENOMEM);
158  return 0;
159 }
160 
162 {
163  CamStudioContext *c = avctx->priv_data;
164  av_freep(&c->decomp_buf);
165  av_frame_free(&c->pic);
166  return 0;
167 }
168 
170  .name = "camstudio",
171  .long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
172  .type = AVMEDIA_TYPE_VIDEO,
173  .id = AV_CODEC_ID_CSCD,
174  .priv_data_size = sizeof(CamStudioContext),
175  .init = decode_init,
176  .close = decode_end,
177  .decode = decode_frame,
178  .capabilities = AV_CODEC_CAP_DR1,
180 };
AVCodec
AVCodec.
Definition: codec.h:202
stride
int stride
Definition: mace.c:144
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: cscd.c:161
FF_CODEC_CAP_INIT_THREADSAFE
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:42
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
data
const char data[16]
Definition: mxf.c:143
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: cscd.c:131
CamStudioContext::height
int height
Definition: cscd.c:35
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:99
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
copy_frame_default
static void copy_frame_default(AVFrame *f, const uint8_t *src, int linelen, int height)
Definition: cscd.c:40
CamStudioContext::decomp_buf
unsigned char * decomp_buf
Definition: cscd.c:37
add_frame_default
static void add_frame_default(AVFrame *f, const uint8_t *src, int linelen, int height)
Definition: cscd.c:53
f
#define f(width, name)
Definition: cbs_vp9.c:255
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: cscd.c:67
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
src
#define src
Definition: vp8dsp.c:255
AV_PIX_FMT_BGR0
@ AV_PIX_FMT_BGR0
packed BGR 8:8:8, 32bpp, BGRXBGRX... X=unused/undefined
Definition: pixfmt.h:230
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
for
for(j=16;j >0;--j)
Definition: h264pred_template.c:469
av_lzo1x_decode
int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen)
Decodes LZO 1x compressed data.
Definition: lzo.c:134
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:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:327
CamStudioContext
Definition: cscd.c:33
CamStudioContext::bpp
int bpp
Definition: cscd.c:35
height
#define height
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1418
AV_PIX_FMT_RGB555LE
@ AV_PIX_FMT_RGB555LE
packed RGB 5:5:5, 16bpp, (msb)1X 5R 5G 5B(lsb), little-endian, X=unused/undefined
Definition: pixfmt.h:108
ff_cscd_decoder
const AVCodec ff_cscd_decoder
Definition: cscd.c:169
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AV_LZO_OUTPUT_PADDING
#define AV_LZO_OUTPUT_PADDING
Definition: lzo.h:47
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: internal.h:50
common.h
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
AVCodecContext::height
int height
Definition: avcodec.h:556
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
avcodec.h
ff_reget_buffer
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:1759
ret
ret
Definition: filter_design.txt:187
AV_CODEC_ID_CSCD
@ AV_CODEC_ID_CSCD
Definition: codec_id.h:129
CamStudioContext::pic
AVFrame * pic
Definition: cscd.c:34
lzo.h
AVCodecContext
main external API structure.
Definition: avcodec.h:383
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
CamStudioContext::linelen
int linelen
Definition: cscd.c:35
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVPacket
This structure stores compressed data.
Definition: packet.h:350
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:556
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
CamStudioContext::decomp_size
unsigned int decomp_size
Definition: cscd.c:36