Libav
cyuv.c
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1 /*
2  * Creative YUV (CYUV) Video Decoder
3  * by Mike Melanson (melanson@pcisys.net)
4  * based on "Creative YUV (CYUV) stream format for AVI":
5  * http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt
6  *
7  * Copyright (C) 2003 the ffmpeg project
8  *
9  * This file is part of Libav.
10  *
11  * Libav is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2.1 of the License, or (at your option) any later version.
15  *
16  * Libav is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19  * Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with Libav; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24  */
25 
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include "avcodec.h"
36 #include "internal.h"
37 #include "libavutil/internal.h"
38 
39 
40 typedef struct CyuvDecodeContext {
42  int width, height;
44 
46 {
47  CyuvDecodeContext *s = avctx->priv_data;
48 
49  s->avctx = avctx;
50  s->width = avctx->width;
51  /* width needs to be divisible by 4 for this codec to work */
52  if (s->width & 0x3)
53  return AVERROR_INVALIDDATA;
54  s->height = avctx->height;
55  avctx->pix_fmt = AV_PIX_FMT_YUV411P;
56 
57  return 0;
58 }
59 
61  void *data, int *got_frame,
62  AVPacket *avpkt)
63 {
64  const uint8_t *buf = avpkt->data;
65  int buf_size = avpkt->size;
66  CyuvDecodeContext *s=avctx->priv_data;
67  AVFrame *frame = data;
68 
69  unsigned char *y_plane;
70  unsigned char *u_plane;
71  unsigned char *v_plane;
72  int y_ptr;
73  int u_ptr;
74  int v_ptr;
75 
76  /* prediction error tables (make it clear that they are signed values) */
77  const signed char *y_table = (const signed char*)buf + 0;
78  const signed char *u_table = (const signed char*)buf + 16;
79  const signed char *v_table = (const signed char*)buf + 32;
80 
81  unsigned char y_pred, u_pred, v_pred;
82  int stream_ptr;
83  unsigned char cur_byte;
84  int pixel_groups;
85  int ret;
86 
87  if (avctx->codec_id == AV_CODEC_ID_AURA) {
88  y_table = u_table;
89  u_table = v_table;
90  }
91  /* sanity check the buffer size: A buffer has 3x16-bytes tables
92  * followed by (height) lines each with 3 bytes to represent groups
93  * of 4 pixels. Thus, the total size of the buffer ought to be:
94  * (3 * 16) + height * (width * 3 / 4) */
95  if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
96  av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
97  buf_size, 48 + s->height * (s->width * 3 / 4));
98  return AVERROR_INVALIDDATA;
99  }
100 
101  /* pixel data starts 48 bytes in, after 3x16-byte tables */
102  stream_ptr = 48;
103 
104  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
105  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
106  return ret;
107  }
108 
109  y_plane = frame->data[0];
110  u_plane = frame->data[1];
111  v_plane = frame->data[2];
112 
113  /* iterate through each line in the height */
114  for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
115  y_ptr < (s->height * frame->linesize[0]);
116  y_ptr += frame->linesize[0] - s->width,
117  u_ptr += frame->linesize[1] - s->width / 4,
118  v_ptr += frame->linesize[2] - s->width / 4) {
119 
120  /* reset predictors */
121  cur_byte = buf[stream_ptr++];
122  u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
123  y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
124 
125  cur_byte = buf[stream_ptr++];
126  v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
127  y_pred += y_table[cur_byte & 0x0F];
128  y_plane[y_ptr++] = y_pred;
129 
130  cur_byte = buf[stream_ptr++];
131  y_pred += y_table[cur_byte & 0x0F];
132  y_plane[y_ptr++] = y_pred;
133  y_pred += y_table[(cur_byte & 0xF0) >> 4];
134  y_plane[y_ptr++] = y_pred;
135 
136  /* iterate through the remaining pixel groups (4 pixels/group) */
137  pixel_groups = s->width / 4 - 1;
138  while (pixel_groups--) {
139 
140  cur_byte = buf[stream_ptr++];
141  u_pred += u_table[(cur_byte & 0xF0) >> 4];
142  u_plane[u_ptr++] = u_pred;
143  y_pred += y_table[cur_byte & 0x0F];
144  y_plane[y_ptr++] = y_pred;
145 
146  cur_byte = buf[stream_ptr++];
147  v_pred += v_table[(cur_byte & 0xF0) >> 4];
148  v_plane[v_ptr++] = v_pred;
149  y_pred += y_table[cur_byte & 0x0F];
150  y_plane[y_ptr++] = y_pred;
151 
152  cur_byte = buf[stream_ptr++];
153  y_pred += y_table[cur_byte & 0x0F];
154  y_plane[y_ptr++] = y_pred;
155  y_pred += y_table[(cur_byte & 0xF0) >> 4];
156  y_plane[y_ptr++] = y_pred;
157 
158  }
159  }
160 
161  *got_frame = 1;
162 
163  return buf_size;
164 }
165 
166 #if CONFIG_AURA_DECODER
167 AVCodec ff_aura_decoder = {
168  .name = "aura",
169  .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
170  .type = AVMEDIA_TYPE_VIDEO,
171  .id = AV_CODEC_ID_AURA,
172  .priv_data_size = sizeof(CyuvDecodeContext),
175  .capabilities = CODEC_CAP_DR1,
176 };
177 #endif
178 
179 #if CONFIG_CYUV_DECODER
180 AVCodec ff_cyuv_decoder = {
181  .name = "cyuv",
182  .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
183  .type = AVMEDIA_TYPE_VIDEO,
184  .id = AV_CODEC_ID_CYUV,
185  .priv_data_size = sizeof(CyuvDecodeContext),
188  .capabilities = CODEC_CAP_DR1,
189 };
190 #endif
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
int size
Definition: avcodec.h:974
AVCodecContext * avctx
Definition: cyuv.c:41
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1270
AVCodec.
Definition: avcodec.h:2812
static av_cold int cyuv_decode_init(AVCodecContext *avctx)
Definition: cyuv.c:45
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:275
uint8_t
#define av_cold
Definition: attributes.h:66
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
uint8_t * data
Definition: avcodec.h:973
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:145
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2819
common internal API header
int width
picture width / height.
Definition: avcodec.h:1229
Libavcodec external API header.
enum AVCodecID codec_id
Definition: avcodec.h:1067
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
main external API structure.
Definition: avcodec.h:1050
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:612
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
common internal api header.
static int cyuv_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: cyuv.c:60
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:72
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
void * priv_data
Definition: avcodec.h:1092
This structure stores compressed data.
Definition: avcodec.h:950