tmv.c
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1 /*
2  * 8088flex TMV video decoder
3  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
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 
29 #include "avcodec.h"
30 
31 #include "cga_data.h"
32 
33 typedef struct TMVContext {
35 } TMVContext;
36 
37 static int tmv_decode_frame(AVCodecContext *avctx, void *data,
38  int *data_size, AVPacket *avpkt)
39 {
40  TMVContext *tmv = avctx->priv_data;
41  const uint8_t *src = avpkt->data;
42  uint8_t *dst;
43  unsigned char_cols = avctx->width >> 3;
44  unsigned char_rows = avctx->height >> 3;
45  unsigned x, y, fg, bg, c;
46 
47  if (tmv->pic.data[0])
48  avctx->release_buffer(avctx, &tmv->pic);
49 
50  if (avctx->get_buffer(avctx, &tmv->pic) < 0) {
51  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
52  return -1;
53  }
54 
55  if (avpkt->size < 2*char_rows*char_cols) {
56  av_log(avctx, AV_LOG_ERROR,
57  "Input buffer too small, truncated sample?\n");
58  *data_size = 0;
59  return -1;
60  }
61 
63  tmv->pic.key_frame = 1;
64  dst = tmv->pic.data[0];
65 
66  tmv->pic.palette_has_changed = 1;
67  memcpy(tmv->pic.data[1], ff_cga_palette, 16 * 4);
68 
69  for (y = 0; y < char_rows; y++) {
70  for (x = 0; x < char_cols; x++) {
71  c = *src++;
72  bg = *src >> 4;
73  fg = *src++ & 0xF;
74  ff_draw_pc_font(dst + x * 8, tmv->pic.linesize[0],
75  ff_cga_font, 8, c, fg, bg);
76  }
77  dst += tmv->pic.linesize[0] * 8;
78  }
79 
80  *data_size = sizeof(AVFrame);
81  *(AVFrame *)data = tmv->pic;
82  return avpkt->size;
83 }
84 
86 {
87  avctx->pix_fmt = PIX_FMT_PAL8;
88  return 0;
89 }
90 
92 {
93  TMVContext *tmv = avctx->priv_data;
94 
95  if (tmv->pic.data[0])
96  avctx->release_buffer(avctx, &tmv->pic);
97 
98  return 0;
99 }
100 
102  .name = "tmv",
103  .type = AVMEDIA_TYPE_VIDEO,
104  .id = CODEC_ID_TMV,
105  .priv_data_size = sizeof(TMVContext),
109  .capabilities = CODEC_CAP_DR1,
110  .long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
111 };
int(* get_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called at the beginning of each frame to get a buffer for it.
Definition: avcodec.h:1726
enum PixelFormat pix_fmt
Pixel format, see PIX_FMT_xxx.
Definition: avcodec.h:1426
const uint8_t ff_cga_font[2048]
Definition: cga_data.c:29
Audio Video Frame.
Definition: avcodec.h:985
Definition: tmv.c:33
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 int tmv_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
Definition: tmv.c:37
AVCodec.
Definition: avcodec.h:3189
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
CGA/EGA/VGA ROM data.
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
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
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
AVCodec ff_tmv_decoder
Definition: tmv.c:101
enum AVPictureType pict_type
Picture type of the frame, see ?_TYPE below.
Definition: avcodec.h:1029
int width
picture width / height.
Definition: avcodec.h:1408
struct AVFrame AVFrame
Audio Video Frame.
static av_cold int tmv_decode_close(AVCodecContext *avctx)
Definition: tmv.c:91
void ff_draw_pc_font(uint8_t *dst, int linesize, const uint8_t *font, int font_height, int ch, int fg, int bg)
Draw CGA/EGA/VGA font to 8-bit pixel buffer.
Definition: cga_data.c:435
external API header
struct TMVContext TMVContext
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
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: avcodec.h:1188
const uint32_t ff_cga_palette[16]
Definition: cga_data.c:419
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
AVFrame pic
Definition: tmv.c:34
8 bit with PIX_FMT_RGB32 palette
Definition: pixfmt.h:75
void * priv_data
Definition: avcodec.h:1531
int key_frame
1 -> keyframe, 0-> not
Definition: avcodec.h:1022
static av_cold int tmv_decode_init(AVCodecContext *avctx)
Definition: tmv.c:85