FFmpeg: libavcodec/avs.c Source File

FFmpeg
avs.c
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1 /*
2  * AVS video decoder.
3  * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
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 "get_bits.h"
24 #include "internal.h"
25 
26  typedef struct AvsContext {
27   AVFrame *frame;
28 } AvsContext;
29 
30  typedef enum {
31   AVS_VIDEO = 0x01,
32   AVS_AUDIO = 0x02,
33   AVS_PALETTE = 0x03,
34   AVS_GAME_DATA = 0x04,
35 } AvsBlockType;
36 
37  typedef enum {
38   AVS_I_FRAME = 0x00,
39   AVS_P_FRAME_3X3 = 0x01,
40   AVS_P_FRAME_2X2 = 0x02,
41   AVS_P_FRAME_2X3 = 0x03,
42 } AvsVideoSubType;
43 
44 
45 static int
46  avs_decode_frame(AVCodecContext * avctx,
47  void *data, int *got_frame, AVPacket *avpkt)
48 {
49  const uint8_t *buf = avpkt->data;
50  const uint8_t *buf_end = avpkt->data + avpkt->size;
51  int buf_size = avpkt->size;
52  AvsContext *const avs = avctx->priv_data;
53  AVFrame *picture = data;
54  AVFrame *const p = avs->frame;
55  const uint8_t *table, *vect;
56  uint8_t *out;
57  int i, j, x, y, stride, ret, vect_w = 3, vect_h = 3;
58  AvsVideoSubType sub_type;
59  AvsBlockType type;
60  GetBitContext change_map = {0}; //init to silence warning
61 
62  if ((ret = ff_reget_buffer(avctx, p, 0)) < 0)
63  return ret;
64  p->pict_type = AV_PICTURE_TYPE_P;
65  p->key_frame = 0;
66 
67  out = p->data[0];
68  stride = p->linesize[0];
69 
70  if (buf_end - buf < 4)
71  return AVERROR_INVALIDDATA;
72  sub_type = buf[0];
73  type = buf[1];
74  buf += 4;
75 
76  if (type == AVS_PALETTE) {
77  int first, last;
78  uint32_t *pal = (uint32_t *) p->data[1];
79 
80  first = AV_RL16(buf);
81  last = first + AV_RL16(buf + 2);
82  if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first))
83  return AVERROR_INVALIDDATA;
84  buf += 4;
85  for (i=first; i<last; i++, buf+=3) {
86  pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2);
87  pal[i] |= 0xFFU << 24 | (pal[i] >> 6) & 0x30303;
88  }
89 
90  sub_type = buf[0];
91  type = buf[1];
92  buf += 4;
93  }
94 
95  if (type != AVS_VIDEO)
96  return AVERROR_INVALIDDATA;
97 
98  switch (sub_type) {
99  case AVS_I_FRAME:
100  p->pict_type = AV_PICTURE_TYPE_I;
101  p->key_frame = 1;
102  case AVS_P_FRAME_3X3:
103  vect_w = 3;
104  vect_h = 3;
105  break;
106 
107  case AVS_P_FRAME_2X2:
108  vect_w = 2;
109  vect_h = 2;
110  break;
111 
112  case AVS_P_FRAME_2X3:
113  vect_w = 2;
114  vect_h = 3;
115  break;
116 
117  default:
118  return AVERROR_INVALIDDATA;
119  }
120 
121  if (buf_end - buf < 256 * vect_w * vect_h)
122  return AVERROR_INVALIDDATA;
123  table = buf + (256 * vect_w * vect_h);
124  if (sub_type != AVS_I_FRAME) {
125  int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h);
126  if (buf_end - table < map_size)
127  return AVERROR_INVALIDDATA;
128  init_get_bits(&change_map, table, map_size * 8);
129  table += map_size;
130  }
131 
132  for (y=0; y<198; y+=vect_h) {
133  for (x=0; x<318; x+=vect_w) {
134  if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) {
135  if (buf_end - table < 1)
136  return AVERROR_INVALIDDATA;
137  vect = &buf[*table++ * (vect_w * vect_h)];
138  for (j=0; j<vect_w; j++) {
139  out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j];
140  out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j];
141  if (vect_h == 3)
142  out[(y + 2) * stride + x + j] =
143  vect[(2 * vect_w) + j];
144  }
145  }
146  }
147  if (sub_type != AVS_I_FRAME)
148  align_get_bits(&change_map);
149  }
150 
151  if ((ret = av_frame_ref(picture, p)) < 0)
152  return ret;
153  *got_frame = 1;
154 
155  return buf_size;
156 }
157 
158  static av_cold int avs_decode_init(AVCodecContext * avctx)
159 {
160  AvsContext *s = avctx->priv_data;
161 
162  s->frame = av_frame_alloc();
163  if (!s->frame)
164  return AVERROR(ENOMEM);
165 
166  avctx->pix_fmt = AV_PIX_FMT_PAL8;
167 
168  return ff_set_dimensions(avctx, 318, 198);
169 }
170 
171  static av_cold int avs_decode_end(AVCodecContext *avctx)
172 {
173  AvsContext *s = avctx->priv_data;
174  av_frame_free(&s->frame);
175  return 0;
176 }
177 
178 
179  const AVCodec ff_avs_decoder = {
180  .name = "avs",
181  .long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"),
182  .type = AVMEDIA_TYPE_VIDEO,
183  .id = AV_CODEC_ID_AVS,
184  .priv_data_size = sizeof(AvsContext),
185  .init = avs_decode_init,
186  .decode = avs_decode_frame,
187  .close = avs_decode_end,
188  .capabilities = AV_CODEC_CAP_DR1,
189  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
190 };
AVCodec
AVCodec.
Definition: codec.h:202
stride
int stride
Definition: mace.c:144
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
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
AVS_VIDEO
@ AVS_VIDEO
Definition: avs.c:31
out
FILE * out
Definition: movenc.c:54
AvsContext::frame
AVFrame * frame
Definition: avs.c:27
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:109
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:317
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
avs_decode_end
static av_cold int avs_decode_end(AVCodecContext *avctx)
Definition: avs.c:171
table
static const uint16_t table[]
Definition: prosumer.c:206
data
const char data[16]
Definition: mxf.c:143
AVS_AUDIO
@ AVS_AUDIO
Definition: avs.c:32
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:660
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:338
init
static int init
Definition: av_tx.c:47
ff_avs_decoder
const AVCodec ff_avs_decoder
Definition: avs.c:179
U
#define U(x)
Definition: vp56_arith.h:37
GetBitContext
Definition: get_bits.h:62
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:409
type
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 type
Definition: writing_filters.txt:86
AvsBlockType
AvsBlockType
Definition: avs.c:30
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:97
avs_decode_init
static av_cold int avs_decode_init(AVCodecContext *avctx)
Definition: avs.c:158
first
trying all byte sequences megabyte in length and selecting the best looking sequence will yield cases to try But first
Definition: rate_distortion.txt:12
AVS_GAME_DATA
@ AVS_GAME_DATA
Definition: avs.c:34
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
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVS_P_FRAME_2X2
@ AVS_P_FRAME_2X2
Definition: avs.c:40
get_bits.h
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
AVS_P_FRAME_3X3
@ AVS_P_FRAME_3X3
Definition: avs.c:39
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:499
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
AvsVideoSubType
AvsVideoSubType
Definition: avs.c:37
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:414
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:325
AVS_I_FRAME
@ AVS_I_FRAME
Definition: avs.c:38
AvsContext
Definition: avs.c:26
AVS_PALETTE
@ AVS_PALETTE
Definition: avs.c:33
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AV_CODEC_ID_AVS
@ AV_CODEC_ID_AVS
Definition: codec_id.h:132
avs_decode_frame
static int avs_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: avs.c:46
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
AVS_P_FRAME_2X3
@ AVS_P_FRAME_2X3
Definition: avs.c:41
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
align_get_bits
static const uint8_t * align_get_bits(GetBitContext *s)
Definition: get_bits.h:694
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
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:86
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVPacket
This structure stores compressed data.
Definition: packet.h:350
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:362
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
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