bethsoftvideo.c
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1 /*
2  * Bethesda VID video decoder
3  * Copyright (C) 2007 Nicholas Tung
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
30 #include "libavutil/common.h"
31 #include "dsputil.h"
32 #include "bethsoftvideo.h"
33 #include "bytestream.h"
34 
35 typedef struct BethsoftvidContext {
39 
41 {
42  BethsoftvidContext *vid = avctx->priv_data;
43  vid->frame.reference = 1;
46  avctx->pix_fmt = PIX_FMT_PAL8;
47  return 0;
48 }
49 
51 {
52  uint32_t *palette = (uint32_t *)ctx->frame.data[1];
53  int a;
54 
55  if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
56  return AVERROR_INVALIDDATA;
57 
58  for(a = 0; a < 256; a++){
59  palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
60  }
61  ctx->frame.palette_has_changed = 1;
62  return 256*3;
63 }
64 
66  void *data, int *data_size,
67  AVPacket *avpkt)
68 {
69  BethsoftvidContext * vid = avctx->priv_data;
70  char block_type;
71  uint8_t * dst;
72  uint8_t * frame_end;
73  int remaining = avctx->width; // number of bytes remaining on a line
74  const int wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
75  int code;
76  int yoffset;
77 
78  if (avctx->reget_buffer(avctx, &vid->frame)) {
79  av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
80  return -1;
81  }
82 
83  bytestream2_init(&vid->g, avpkt->data, avpkt->size);
84  dst = vid->frame.data[0];
85  frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
86 
87  switch(block_type = bytestream2_get_byte(&vid->g)){
88  case PALETTE_BLOCK: {
89  return set_palette(vid);
90  }
91  case VIDEO_YOFF_P_FRAME:
92  yoffset = bytestream2_get_le16(&vid->g);
93  if(yoffset >= avctx->height)
94  return -1;
95  dst += vid->frame.linesize[0] * yoffset;
96  }
97 
98  // main code
99  while((code = bytestream2_get_byte(&vid->g))){
100  int length = code & 0x7f;
101 
102  // copy any bytes starting at the current position, and ending at the frame width
103  while(length > remaining){
104  if(code < 0x80)
105  bytestream2_get_buffer(&vid->g, dst, remaining);
106  else if(block_type == VIDEO_I_FRAME)
107  memset(dst, bytestream2_peek_byte(&vid->g), remaining);
108  length -= remaining; // decrement the number of bytes to be copied
109  dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
110  remaining = avctx->width;
111  if(dst == frame_end)
112  goto end;
113  }
114 
115  // copy any remaining bytes after / if line overflows
116  if(code < 0x80)
117  bytestream2_get_buffer(&vid->g, dst, length);
118  else if(block_type == VIDEO_I_FRAME)
119  memset(dst, bytestream2_get_byte(&vid->g), length);
120  remaining -= length;
121  dst += length;
122  }
123  end:
124 
125  *data_size = sizeof(AVFrame);
126  *(AVFrame*)data = vid->frame;
127 
128  return avpkt->size;
129 }
130 
132 {
133  BethsoftvidContext * vid = avctx->priv_data;
134  if(vid->frame.data[0])
135  avctx->release_buffer(avctx, &vid->frame);
136  return 0;
137 }
138 
140  .name = "bethsoftvid",
141  .type = AVMEDIA_TYPE_VIDEO,
142  .id = CODEC_ID_BETHSOFTVID,
143  .priv_data_size = sizeof(BethsoftvidContext),
147  .capabilities = CODEC_CAP_DR1,
148  .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
149 };
enum PixelFormat pix_fmt
Pixel format, see PIX_FMT_xxx.
Definition: avcodec.h:1426
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
#define FF_BUFFER_HINTS_VALID
Definition: avcodec.h:880
Audio Video Frame.
Definition: avcodec.h:985
int buffer_hints
codec suggestion on buffer type if != 0
Definition: avcodec.h:1195
void(* release_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called to release buffers which were allocated with get_buffer.
Definition: avcodec.h:1737
int size
Definition: avcodec.h:909
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:138
AVCodec.
Definition: avcodec.h:3189
int(* reget_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called at the beginning of a frame to get cr buffer for it.
Definition: avcodec.h:2336
AVCodec ff_bethsoftvid_decoder
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
#define av_cold
Definition: attributes.h:71
const char data[16]
Definition: mxf.c:60
uint8_t * data
Definition: avcodec.h:908
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:336
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:719
int reference
is this picture used as reference The values for this are the same as the MpegEncContext.picture_structure variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
Definition: avcodec.h:1074
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:266
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:157
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
const char * name
Name of the codec implementation.
Definition: avcodec.h:3196
struct BethsoftvidContext BethsoftvidContext
int width
picture width / height.
Definition: avcodec.h:1408
struct AVFrame AVFrame
Audio Video Frame.
static int bethsoftvid_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
Definition: bethsoftvideo.c:65
static int set_palette(BethsoftvidContext *ctx)
Definition: bethsoftvideo.c:50
#define FF_BUFFER_HINTS_REUSABLE
Definition: avcodec.h:883
static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
Definition: bethsoftvideo.c:40
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
main external API structure.
Definition: avcodec.h:1329
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:327
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
#define FF_BUFFER_HINTS_PRESERVE
Definition: avcodec.h:882
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: avcodec.h:1188
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
int palette
Definition: v4l.c:63
common internal and external API header
8 bit with PIX_FMT_RGB32 palette
Definition: pixfmt.h:75
DSP utils.
void * priv_data
Definition: avcodec.h:1531
GetByteContext g
Definition: bethsoftvideo.c:37