FFmpeg  4.3
c93.c
Go to the documentation of this file.
1 /*
2  * Interplay C93 video decoder
3  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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 #include "avcodec.h"
23 #include "bytestream.h"
24 #include "internal.h"
25 
26 typedef struct C93DecoderContext {
30 
31 typedef enum {
39  C93_NOOP = 0x0E,
40  C93_8X8_INTRA = 0x0F,
41 } C93BlockType;
42 
43 #define WIDTH 320
44 #define HEIGHT 192
45 
46 #define C93_HAS_PALETTE 0x01
47 #define C93_FIRST_FRAME 0x02
48 
49 static av_cold int decode_end(AVCodecContext *avctx)
50 {
51  C93DecoderContext * const c93 = avctx->priv_data;
52 
53  av_frame_free(&c93->pictures[0]);
54  av_frame_free(&c93->pictures[1]);
55 
56  return 0;
57 }
58 
60 {
61  C93DecoderContext *s = avctx->priv_data;
62  avctx->pix_fmt = AV_PIX_FMT_PAL8;
63 
64  s->pictures[0] = av_frame_alloc();
65  s->pictures[1] = av_frame_alloc();
66  if (!s->pictures[0] || !s->pictures[1]) {
67  decode_end(avctx);
68  return AVERROR(ENOMEM);
69  }
70 
71  return 0;
72 }
73 
74 static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
75  uint8_t *from, int offset, int height, int stride)
76 {
77  int i;
78  int width = height;
79  int from_x = offset % WIDTH;
80  int from_y = offset / WIDTH;
81  int overflow = from_x + width - WIDTH;
82 
83  if (!from) {
84  /* silently ignoring predictive blocks in first frame */
85  return 0;
86  }
87 
88  if (from_y + height > HEIGHT) {
89  av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
90  offset);
91  return AVERROR_INVALIDDATA;
92  }
93 
94  if (overflow > 0) {
95  width -= overflow;
96  for (i = 0; i < height; i++) {
97  memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
98  }
99  }
100 
101  for (i = 0; i < height; i++) {
102  memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
103  }
104 
105  return 0;
106 }
107 
108 static inline void draw_n_color(uint8_t *out, int stride, int width,
109  int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
110 {
111  int x, y;
112  for (y = 0; y < height; y++) {
113  if (grps)
114  cols[0] = grps[3 * (y >> 1)];
115  for (x = 0; x < width; x++) {
116  if (grps)
117  cols[1]= grps[(x >> 1) + 1];
118  out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
119  col >>= bpp;
120  }
121  }
122 }
123 
124 static int decode_frame(AVCodecContext *avctx, void *data,
125  int *got_frame, AVPacket *avpkt)
126 {
127  const uint8_t *buf = avpkt->data;
128  int buf_size = avpkt->size;
129  C93DecoderContext * const c93 = avctx->priv_data;
130  AVFrame * const newpic = c93->pictures[c93->currentpic];
131  AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
132  GetByteContext gb;
133  uint8_t *out;
134  int stride, ret, i, x, y, b, bt = 0;
135 
136  if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
137  return ret;
138 
139  c93->currentpic ^= 1;
140 
141  if ((ret = ff_reget_buffer(avctx, newpic, 0)) < 0)
142  return ret;
143 
144  stride = newpic->linesize[0];
145 
146  bytestream2_init(&gb, buf, buf_size);
147  b = bytestream2_get_byte(&gb);
148  if (b & C93_FIRST_FRAME) {
149  newpic->pict_type = AV_PICTURE_TYPE_I;
150  newpic->key_frame = 1;
151  } else {
152  newpic->pict_type = AV_PICTURE_TYPE_P;
153  newpic->key_frame = 0;
154  }
155 
156  for (y = 0; y < HEIGHT; y += 8) {
157  out = newpic->data[0] + y * stride;
158  for (x = 0; x < WIDTH; x += 8) {
159  uint8_t *copy_from = oldpic->data[0];
160  unsigned int offset, j;
161  uint8_t cols[4], grps[4];
162  C93BlockType block_type;
163 
164  if (!bt)
165  bt = bytestream2_get_byte(&gb);
166 
167  block_type= bt & 0x0F;
168  switch (block_type) {
169  case C93_8X8_FROM_PREV:
170  offset = bytestream2_get_le16(&gb);
171  if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
172  return ret;
173  break;
174 
175  case C93_4X4_FROM_CURR:
176  copy_from = newpic->data[0];
177  case C93_4X4_FROM_PREV:
178  for (j = 0; j < 8; j += 4) {
179  for (i = 0; i < 8; i += 4) {
180  int offset = bytestream2_get_le16(&gb);
181  int from_x = offset % WIDTH;
182  int from_y = offset / WIDTH;
183  if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
184  (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
185  avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j);
186  return AVERROR_INVALIDDATA;
187  }
188  if ((ret = copy_block(avctx, &out[j*stride+i],
189  copy_from, offset, 4, stride)) < 0)
190  return ret;
191  }
192  }
193  break;
194 
195  case C93_8X8_2COLOR:
196  bytestream2_get_buffer(&gb, cols, 2);
197  for (i = 0; i < 8; i++) {
198  draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
199  NULL, bytestream2_get_byte(&gb));
200  }
201 
202  break;
203 
204  case C93_4X4_2COLOR:
205  case C93_4X4_4COLOR:
206  case C93_4X4_4COLOR_GRP:
207  for (j = 0; j < 8; j += 4) {
208  for (i = 0; i < 8; i += 4) {
209  if (block_type == C93_4X4_2COLOR) {
210  bytestream2_get_buffer(&gb, cols, 2);
211  draw_n_color(out + i + j*stride, stride, 4, 4,
212  1, cols, NULL, bytestream2_get_le16(&gb));
213  } else if (block_type == C93_4X4_4COLOR) {
214  bytestream2_get_buffer(&gb, cols, 4);
215  draw_n_color(out + i + j*stride, stride, 4, 4,
216  2, cols, NULL, bytestream2_get_le32(&gb));
217  } else {
218  bytestream2_get_buffer(&gb, grps, 4);
219  draw_n_color(out + i + j*stride, stride, 4, 4,
220  1, cols, grps, bytestream2_get_le16(&gb));
221  }
222  }
223  }
224  break;
225 
226  case C93_NOOP:
227  break;
228 
229  case C93_8X8_INTRA:
230  for (j = 0; j < 8; j++)
231  bytestream2_get_buffer(&gb, out + j*stride, 8);
232  break;
233 
234  default:
235  av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
236  block_type, x, y);
237  return AVERROR_INVALIDDATA;
238  }
239  bt >>= 4;
240  out += 8;
241  }
242  }
243 
244  if (b & C93_HAS_PALETTE) {
245  uint32_t *palette = (uint32_t *) newpic->data[1];
246  for (i = 0; i < 256; i++) {
247  palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
248  }
249  newpic->palette_has_changed = 1;
250  } else {
251  if (oldpic->data[1])
252  memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
253  }
254 
255  if ((ret = av_frame_ref(data, newpic)) < 0)
256  return ret;
257  *got_frame = 1;
258 
259  return buf_size;
260 }
261 
263  .name = "c93",
264  .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
265  .type = AVMEDIA_TYPE_VIDEO,
266  .id = AV_CODEC_ID_C93,
267  .priv_data_size = sizeof(C93DecoderContext),
268  .init = decode_init,
269  .close = decode_end,
270  .decode = decode_frame,
271  .capabilities = AV_CODEC_CAP_DR1,
272  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
273 };
C93DecoderContext::currentpic
int currentpic
Definition: c93.c:28
AVCodec
AVCodec.
Definition: codec.h:190
stride
int stride
Definition: mace.c:144
C93_FIRST_FRAME
#define C93_FIRST_FRAME
Definition: c93.c:47
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: c93.c:124
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:40
C93DecoderContext
Definition: c93.c:26
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
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
out
FILE * out
Definition: movenc.c:54
C93_8X8_2COLOR
@ C93_8X8_2COLOR
Definition: c93.c:35
GetByteContext
Definition: bytestream.h:33
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:355
b
#define b
Definition: input.c:41
data
const char data[16]
Definition: mxf.c:91
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:314
U
#define U(x)
Definition: vp56_arith.h:37
x
FFmpeg Automated Testing Environment ************************************Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server Uploading new samples to the fate suite FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg’s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg’s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass ‘ target exec’ to ‘configure’ or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script ‘tests fate sh’ from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at ‘doc fate_config sh template’ Create a configuration that suits your based on the configuration template The ‘slot’ configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern ‘ARCH OS COMPILER COMPILER VERSION’ The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the ‘fate_recv’ variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration it may help to try out the ‘ssh’ command with one or more ‘ v’ options You should get detailed output concerning your SSH configuration and the authentication process The only thing left is to automate the execution of the fate sh script and the synchronisation of the samples directory Uploading new samples to the fate suite *****************************************If you need a sample uploaded send a mail to samples request This is for developers who have an account on the fate suite server If you upload new please make sure they are as small as space on each network bandwidth and so on benefit from smaller test cases Also keep in mind older checkouts use existing sample that means in practice generally do not remove or overwrite files as it likely would break older checkouts or releases Also all needed samples for a commit should be ideally before the push If you need an account for frequently uploading samples or you wish to help others by doing that send a mail to ffmpeg devel rsync vauL Duo x
Definition: fate.txt:150
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:378
to
FFmpeg Automated Testing Environment ************************************Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server Uploading new samples to the fate suite FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg’s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg’s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass ‘ target exec’ to ‘configure’ or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script ‘tests fate sh’ from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at ‘doc fate_config sh template’ Create a configuration that suits your based on the configuration template The ‘slot’ configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern ‘ARCH OS COMPILER COMPILER VERSION’ The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the ‘fate_recv’ variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration it may help to try out the ‘ssh’ command with one or more ‘ v’ options You should get detailed output concerning your SSH configuration and the authentication process The only thing left is to automate the execution of the fate sh script and the synchronisation of the samples directory Uploading new samples to the fate suite *****************************************If you need a sample uploaded send a mail to samples request This is for developers who have an account on the fate suite server If you upload new please make sure they are as small as space on each network bandwidth and so on benefit from smaller test cases Also keep in mind older checkouts use existing sample that means in practice generally do not remove or overwrite files as it likely would break older checkouts or releases Also all needed samples for a commit should be ideally before the push If you need an account for frequently uploading samples or you wish to help others by doing that send a mail to ffmpeg devel rsync vauL Duo ug o o X fate suite ffmpeg Duo ug o o X fate suite fate suite ffmpeg Duo ug o o X fate suite fate suite ffmpeg can be set to
Definition: fate.txt:178
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
C93_NOOP
@ C93_NOOP
Definition: c93.c:39
C93_4X4_2COLOR
@ C93_4X4_2COLOR
Definition: c93.c:36
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
C93_HAS_PALETTE
#define C93_HAS_PALETTE
Definition: c93.c:46
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
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:257
from
const char * from
Definition: jacosubdec.c:65
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: c93.c:59
C93BlockType
C93BlockType
Definition: c93.c:31
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: c93.c:49
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
NULL
#define NULL
Definition: coverity.c:32
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
bytestream2_get_buffer
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
C93_4X4_FROM_CURR
@ C93_4X4_FROM_CURR
Definition: c93.c:34
for
for(j=16;j >0;--j)
Definition: h264pred_template.c:469
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:383
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
AVPacket::size
int size
Definition: packet.h:356
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:186
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:444
C93_8X8_FROM_PREV
@ C93_8X8_FROM_PREV
Definition: c93.c:32
WIDTH
#define WIDTH
Definition: c93.c:43
height
#define height
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
C93_4X4_4COLOR
@ C93_4X4_4COLOR
Definition: c93.c:38
C93_4X4_4COLOR_GRP
@ C93_4X4_4COLOR_GRP
Definition: c93.c:37
copy_from
static int copy_from(IpvideoContext *s, AVFrame *src, AVFrame *dst, int delta_x, int delta_y)
Definition: interplayvideo.c:78
HEIGHT
#define HEIGHT
Definition: c93.c:44
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
uint8_t
uint8_t
Definition: audio_convert.c:194
AV_CODEC_ID_C93
@ AV_CODEC_ID_C93
Definition: codec_id.h:151
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:197
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:736
avcodec.h
ff_c93_decoder
AVCodec ff_c93_decoder
Definition: c93.c:262
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
draw_n_color
static void draw_n_color(uint8_t *out, int stride, int width, int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
Definition: c93.c:108
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:1960
ret
ret
Definition: filter_design.txt:187
C93_8X8_INTRA
@ C93_8X8_INTRA
Definition: c93.c:40
AVCodecContext
main external API structure.
Definition: avcodec.h:526
AVFrame::palette_has_changed
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:457
C93DecoderContext::pictures
AVFrame * pictures[2]
Definition: c93.c:27
C93_4X4_FROM_PREV
@ C93_4X4_FROM_PREV
Definition: c93.c:33
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:104
overflow
Undefined Behavior In the C some operations are like signed integer overflow
Definition: undefined.txt:3
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:39
AVPacket
This structure stores compressed data.
Definition: packet.h:332
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:553
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:331
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:59
copy_block
static int copy_block(AVCodecContext *avctx, uint8_t *to, uint8_t *from, int offset, int height, int stride)
Definition: c93.c:74