FFmpeg
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 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  * @brief Bethesda Softworks VID Video Decoder
25  * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
26  * @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
27  * @see http://www.svatopluk.com/andux/docs/dfvid.html
28  */
29 
30 #include "libavutil/common.h"
31 #include "avcodec.h"
32 #include "bethsoftvideo.h"
33 #include "bytestream.h"
34 #include "internal.h"
35 
36 typedef struct BethsoftvidContext {
40 
42 {
43  BethsoftvidContext *vid = avctx->priv_data;
44  avctx->pix_fmt = AV_PIX_FMT_PAL8;
45 
46  vid->frame = av_frame_alloc();
47  if (!vid->frame)
48  return AVERROR(ENOMEM);
49 
50  return 0;
51 }
52 
54 {
55  uint32_t *palette = (uint32_t *)ctx->frame->data[1];
56  int a;
57 
58  if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
59  return AVERROR_INVALIDDATA;
60 
61  for(a = 0; a < 256; a++){
62  palette[a] = 0xFFU << 24 | bytestream2_get_be24u(&ctx->g) * 4;
63  palette[a] |= palette[a] >> 6 & 0x30303;
64  }
65  ctx->frame->palette_has_changed = 1;
66  return 0;
67 }
68 
70  void *data, int *got_frame,
71  AVPacket *avpkt)
72 {
73  BethsoftvidContext * vid = avctx->priv_data;
74  char block_type;
75  uint8_t * dst;
77  int remaining = avctx->width; // number of bytes remaining on a line
78  int wrap_to_next_line;
79  int code, ret;
80  int yoffset;
81 
82  if ((ret = ff_reget_buffer(avctx, vid->frame, 0)) < 0)
83  return ret;
84  wrap_to_next_line = vid->frame->linesize[0] - avctx->width;
85 
86  if (avpkt->side_data_elems > 0 &&
87  avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) {
88  bytestream2_init(&vid->g, avpkt->side_data[0].data,
89  avpkt->side_data[0].size);
90  if ((ret = set_palette(vid)) < 0)
91  return ret;
92  }
93 
94  bytestream2_init(&vid->g, avpkt->data, avpkt->size);
95  dst = vid->frame->data[0];
96  frame_end = vid->frame->data[0] + vid->frame->linesize[0] * avctx->height;
97 
98  switch(block_type = bytestream2_get_byte(&vid->g)){
99  case PALETTE_BLOCK: {
100  *got_frame = 0;
101  if ((ret = set_palette(vid)) < 0) {
102  av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
103  return ret;
104  }
105  return bytestream2_tell(&vid->g);
106  }
107  case VIDEO_YOFF_P_FRAME:
108  yoffset = bytestream2_get_le16(&vid->g);
109  if(yoffset >= avctx->height)
110  return AVERROR_INVALIDDATA;
111  dst += vid->frame->linesize[0] * yoffset;
112  case VIDEO_P_FRAME:
113  case VIDEO_I_FRAME:
114  break;
115  default:
116  return AVERROR_INVALIDDATA;
117  }
118 
119  // main code
120  while((code = bytestream2_get_byte(&vid->g))){
121  int length = code & 0x7f;
122 
123  // copy any bytes starting at the current position, and ending at the frame width
124  while(length > remaining){
125  if(code < 0x80)
126  bytestream2_get_buffer(&vid->g, dst, remaining);
127  else if(block_type == VIDEO_I_FRAME)
128  memset(dst, bytestream2_peek_byte(&vid->g), remaining);
129  length -= remaining; // decrement the number of bytes to be copied
130  dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
131  remaining = avctx->width;
132  if(dst == frame_end)
133  goto end;
134  }
135 
136  // copy any remaining bytes after / if line overflows
137  if(code < 0x80)
138  bytestream2_get_buffer(&vid->g, dst, length);
139  else if(block_type == VIDEO_I_FRAME)
140  memset(dst, bytestream2_get_byte(&vid->g), length);
141  remaining -= length;
142  dst += length;
143  }
144  end:
145 
146  if ((ret = av_frame_ref(data, vid->frame)) < 0)
147  return ret;
148 
149  *got_frame = 1;
150 
151  return avpkt->size;
152 }
153 
155 {
156  BethsoftvidContext * vid = avctx->priv_data;
157  av_frame_free(&vid->frame);
158  return 0;
159 }
160 
162  .name = "bethsoftvid",
163  .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
164  .type = AVMEDIA_TYPE_VIDEO,
166  .priv_data_size = sizeof(BethsoftvidContext),
168  .close = bethsoftvid_decode_end,
170  .capabilities = AV_CODEC_CAP_DR1,
171  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
172 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1481
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1778
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
AVCodec.
Definition: avcodec.h:3492
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
AVCodec ff_bethsoftvid_decoder
#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
uint8_t
#define av_cold
Definition: attributes.h:82
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
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:443
uint8_t * data
Definition: avcodec.h:1480
uint8_t * data
Definition: avcodec.h:1424
#define av_log(a,...)
#define U(x)
Definition: vp56_arith.h:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
An AV_PKT_DATA_PALETTE side data packet contains exactly AVPALETTE_SIZE bytes worth of palette...
Definition: avcodec.h:1193
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
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:2015
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
enum AVPacketSideDataType type
Definition: avcodec.h:1426
GLsizei GLsizei * length
Definition: opengl_enc.c:114
const char * name
Name of the codec implementation.
Definition: avcodec.h:3499
int side_data_elems
Definition: avcodec.h:1492
static int bethsoftvid_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: bethsoftvideo.c:69
static void frame_end(MpegEncContext *s)
int width
picture width / height.
Definition: avcodec.h:1741
AVFormatContext * ctx
Definition: movenc.c:48
static int set_palette(BethsoftvidContext *ctx)
Definition: bethsoftvideo.c:53
if(ret)
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:188
Libavcodec external API header.
static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
Definition: bethsoftvideo.c:41
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
main external API structure.
Definition: avcodec.h:1568
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:452
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
AVPacketSideData * side_data
Additional packet data that can be provided by the container.
Definition: avcodec.h:1491
common internal api header.
common internal and external API header
void * priv_data
Definition: avcodec.h:1595
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
This structure stores compressed data.
Definition: avcodec.h:1457
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984
GetByteContext g
Definition: bethsoftvideo.c:38