FFmpeg
tscc.c
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1 /*
2  * TechSmith Camtasia decoder
3  * Copyright (c) 2004 Konstantin Shishkov
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  * TechSmith Camtasia decoder
25  *
26  * Fourcc: TSCC
27  *
28  * Codec is very simple:
29  * it codes picture (picture difference, really)
30  * with algorithm almost identical to Windows RLE8,
31  * only without padding and with greater pixel sizes,
32  * then this coded picture is packed with ZLib
33  *
34  * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
35  */
36 
37 #include <stdio.h>
38 #include <stdlib.h>
39 
40 #include "avcodec.h"
41 #include "decode.h"
42 #include "internal.h"
43 #include "msrledec.h"
44 
45 #include <zlib.h>
46 
47 typedef struct TsccContext {
48 
51 
52  // Bits per pixel
53  int bpp;
54  // Decompressed data size
55  unsigned int decomp_size;
56  // Decompression buffer
57  unsigned char* decomp_buf;
59  int height;
61  z_stream zstream;
62 
63  uint32_t pal[256];
64 } CamtasiaContext;
65 
66 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
67  AVPacket *avpkt)
68 {
69  const uint8_t *buf = avpkt->data;
70  int buf_size = avpkt->size;
71  CamtasiaContext * const c = avctx->priv_data;
72  AVFrame *frame = c->frame;
73  int ret;
74  int palette_has_changed = 0;
75 
76  if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
77  palette_has_changed = ff_copy_palette(c->pal, avpkt, avctx);
78  }
79 
80  ret = inflateReset(&c->zstream);
81  if (ret != Z_OK) {
82  av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
83  return AVERROR_UNKNOWN;
84  }
85  c->zstream.next_in = buf;
86  c->zstream.avail_in = buf_size;
87  c->zstream.next_out = c->decomp_buf;
88  c->zstream.avail_out = c->decomp_size;
89  ret = inflate(&c->zstream, Z_FINISH);
90  // Z_DATA_ERROR means empty picture
91  if (ret == Z_DATA_ERROR && !palette_has_changed) {
92  return buf_size;
93  }
94 
95  if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
96  av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
97  return AVERROR_UNKNOWN;
98  }
99 
100  if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
101  return ret;
102 
103  if (ret != Z_DATA_ERROR) {
104  bytestream2_init(&c->gb, c->decomp_buf,
105  c->decomp_size - c->zstream.avail_out);
106  ff_msrle_decode(avctx, frame, c->bpp, &c->gb);
107  }
108 
109  /* make the palette available on the way out */
110  if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
111  frame->palette_has_changed = palette_has_changed;
112  memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
113  }
114 
115  if ((ret = av_frame_ref(data, frame)) < 0)
116  return ret;
117  *got_frame = 1;
118 
119  /* always report that the buffer was completely consumed */
120  return buf_size;
121 }
122 
124 {
125  CamtasiaContext * const c = avctx->priv_data;
126  int zret; // Zlib return code
127 
128  c->avctx = avctx;
129 
130  c->height = avctx->height;
131 
132  switch(avctx->bits_per_coded_sample){
133  case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
134  case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
135  case 24:
136  avctx->pix_fmt = AV_PIX_FMT_BGR24;
137  break;
138  case 32: avctx->pix_fmt = AV_PIX_FMT_0RGB32; break;
139  default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
140  return AVERROR_PATCHWELCOME;
141  }
142  c->bpp = avctx->bits_per_coded_sample;
143  // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
144  c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
145 
146  /* Allocate decompression buffer */
147  if (c->decomp_size) {
148  if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
149  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
150  return AVERROR(ENOMEM);
151  }
152  }
153 
154  c->zstream.zalloc = Z_NULL;
155  c->zstream.zfree = Z_NULL;
156  c->zstream.opaque = Z_NULL;
157  zret = inflateInit(&c->zstream);
158  if (zret != Z_OK) {
159  av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
160  return AVERROR_UNKNOWN;
161  }
162  c->zlib_init_ok = 1;
163 
164  c->frame = av_frame_alloc();
165  if (!c->frame)
166  return AVERROR(ENOMEM);
167 
168  return 0;
169 }
170 
172 {
173  CamtasiaContext * const c = avctx->priv_data;
174 
175  av_freep(&c->decomp_buf);
176  av_frame_free(&c->frame);
177 
178  if (c->zlib_init_ok)
179  inflateEnd(&c->zstream);
180 
181  return 0;
182 }
183 
185  .name = "camtasia",
186  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
187  .type = AVMEDIA_TYPE_VIDEO,
188  .id = AV_CODEC_ID_TSCC,
189  .priv_data_size = sizeof(CamtasiaContext),
190  .init = decode_init,
191  .close = decode_end,
192  .decode = decode_frame,
193  .capabilities = AV_CODEC_CAP_DR1,
195 };
AVCodec
AVCodec.
Definition: codec.h:202
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
GetByteContext
Definition: bytestream.h:33
TsccContext::height
int height
Definition: tscc.c:59
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
TsccContext::gb
GetByteContext gb
Definition: tscc.c:58
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
TsccContext::frame
AVFrame * frame
Definition: tscc.c:50
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
TsccContext::decomp_size
unsigned int decomp_size
Definition: tscc.c:55
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: tscc.c:66
inflate
static void inflate(uint8_t *dst, const uint8_t *p1, int width, int threshold, const uint8_t *coordinates[], int coord, int maxc)
Definition: vf_neighbor.c:198
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
TsccContext::zstream
z_stream zstream
Definition: tscc.c:61
TsccContext::avctx
AVCodecContext * avctx
Definition: tscc.c:49
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
ff_tscc_decoder
const AVCodec ff_tscc_decoder
Definition: tscc.c:184
decode.h
if
if(ret)
Definition: filter_design.txt:179
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
TsccContext::zlib_init_ok
int zlib_init_ok
Definition: tscc.c:60
msrledec.h
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
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
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
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: tscc.c:171
AVCodecContext::bits_per_coded_sample
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1418
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: tscc.c:123
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
AV_PIX_FMT_RGB555
#define AV_PIX_FMT_RGB555
Definition: pixfmt.h:377
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
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
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
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
AV_PIX_FMT_0RGB32
#define AV_PIX_FMT_0RGB32
Definition: pixfmt.h:366
TsccContext
Definition: tscc.c:47
AVCodecContext
main external API structure.
Definition: avcodec.h:383
TsccContext::pal
uint32_t pal[256]
Definition: tscc.c:63
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_CODEC_ID_TSCC
@ AV_CODEC_ID_TSCC
Definition: codec_id.h:106
TsccContext::bpp
int bpp
Definition: tscc.c:53
ff_msrle_decode
int ff_msrle_decode(AVCodecContext *avctx, AVFrame *pic, int depth, GetByteContext *gb)
Decode stream in MS RLE format into frame.
Definition: msrledec.c:249
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
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
ff_copy_palette
int ff_copy_palette(void *dst, const AVPacket *src, void *logctx)
Check whether the side-data of src contains a palette of size AVPALETTE_SIZE; if so,...
Definition: decode.c:1854
TsccContext::decomp_buf
unsigned char * decomp_buf
Definition: tscc.c:57