FFmpeg
cyuv.c
Go to the documentation of this file.
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 FFmpeg.
10  *
11  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24  */
25 
26 /**
27  * @file
28  * Creative YUV (CYUV) Video Decoder.
29  */
30 
31 #include "config_components.h"
32 
33 #include <string.h>
34 
35 #include "avcodec.h"
36 #include "codec_internal.h"
37 #include "decode.h"
38 #include "libavutil/internal.h"
39 
40 
41 typedef struct CyuvDecodeContext {
43  int width, height;
45 
47 {
48  CyuvDecodeContext *s = avctx->priv_data;
49 
50  s->avctx = avctx;
51  s->width = avctx->width;
52  /* width needs to be divisible by 4 for this codec to work */
53  if (s->width & 0x3)
54  return AVERROR_INVALIDDATA;
55  s->height = avctx->height;
56 
57  return 0;
58 }
59 
61  int *got_frame, AVPacket *avpkt)
62 {
63  const uint8_t *buf = avpkt->data;
64  int buf_size = avpkt->size;
66 
67  unsigned char *y_plane;
68  unsigned char *u_plane;
69  unsigned char *v_plane;
70  int y_ptr;
71  int u_ptr;
72  int v_ptr;
73 
74  /* prediction error tables (make it clear that they are signed values) */
75  const signed char *y_table = (const signed char*)buf + 0;
76  const signed char *u_table = (const signed char*)buf + 16;
77  const signed char *v_table = (const signed char*)buf + 32;
78 
79  unsigned char y_pred, u_pred, v_pred;
80  int stream_ptr;
81  unsigned char cur_byte;
82  int pixel_groups;
83  int rawsize = s->height * FFALIGN(s->width,2) * 2;
84  int ret;
85 
86  if (avctx->codec_id == AV_CODEC_ID_AURA) {
87  y_table = u_table;
88  u_table = v_table;
89  }
90  /* sanity check the buffer size: A buffer has 3x16-bytes tables
91  * followed by (height) lines each with 3 bytes to represent groups
92  * of 4 pixels. Thus, the total size of the buffer ought to be:
93  * (3 * 16) + height * (width * 3 / 4) */
94  if (buf_size == 48 + s->height * (s->width * 3 / 4)) {
95  avctx->pix_fmt = AV_PIX_FMT_YUV411P;
96  } else if(buf_size == rawsize ) {
97  avctx->pix_fmt = AV_PIX_FMT_UYVY422;
98  } else {
99  av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
100  buf_size, 48 + s->height * (s->width * 3 / 4));
101  return AVERROR_INVALIDDATA;
102  }
103 
104  /* pixel data starts 48 bytes in, after 3x16-byte tables */
105  stream_ptr = 48;
106 
107  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
108  return ret;
109 
110  y_plane = frame->data[0];
111  u_plane = frame->data[1];
112  v_plane = frame->data[2];
113 
114  if (buf_size == rawsize) {
115  int linesize = FFALIGN(s->width,2) * 2;
116  y_plane += frame->linesize[0] * s->height;
117  for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) {
118  y_plane -= frame->linesize[0];
119  memcpy(y_plane, buf+stream_ptr, linesize);
120  }
121  } else {
122 
123  /* iterate through each line in the height */
124  for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
125  y_ptr < (s->height * frame->linesize[0]);
126  y_ptr += frame->linesize[0] - s->width,
127  u_ptr += frame->linesize[1] - s->width / 4,
128  v_ptr += frame->linesize[2] - s->width / 4) {
129 
130  /* reset predictors */
131  cur_byte = buf[stream_ptr++];
132  u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
133  y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
134 
135  cur_byte = buf[stream_ptr++];
136  v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
137  y_pred += y_table[cur_byte & 0x0F];
138  y_plane[y_ptr++] = y_pred;
139 
140  cur_byte = buf[stream_ptr++];
141  y_pred += y_table[cur_byte & 0x0F];
142  y_plane[y_ptr++] = y_pred;
143  y_pred += y_table[(cur_byte & 0xF0) >> 4];
144  y_plane[y_ptr++] = y_pred;
145 
146  /* iterate through the remaining pixel groups (4 pixels/group) */
147  pixel_groups = s->width / 4 - 1;
148  while (pixel_groups--) {
149 
150  cur_byte = buf[stream_ptr++];
151  u_pred += u_table[(cur_byte & 0xF0) >> 4];
152  u_plane[u_ptr++] = u_pred;
153  y_pred += y_table[cur_byte & 0x0F];
154  y_plane[y_ptr++] = y_pred;
155 
156  cur_byte = buf[stream_ptr++];
157  v_pred += v_table[(cur_byte & 0xF0) >> 4];
158  v_plane[v_ptr++] = v_pred;
159  y_pred += y_table[cur_byte & 0x0F];
160  y_plane[y_ptr++] = y_pred;
161 
162  cur_byte = buf[stream_ptr++];
163  y_pred += y_table[cur_byte & 0x0F];
164  y_plane[y_ptr++] = y_pred;
165  y_pred += y_table[(cur_byte & 0xF0) >> 4];
166  y_plane[y_ptr++] = y_pred;
167 
168  }
169  }
170  }
171 
172  *got_frame = 1;
173 
174  return buf_size;
175 }
176 
177 #if CONFIG_AURA_DECODER
178 const FFCodec ff_aura_decoder = {
179  .p.name = "aura",
180  CODEC_LONG_NAME("Auravision AURA"),
181  .p.type = AVMEDIA_TYPE_VIDEO,
182  .p.id = AV_CODEC_ID_AURA,
183  .priv_data_size = sizeof(CyuvDecodeContext),
186  .p.capabilities = AV_CODEC_CAP_DR1,
187 };
188 #endif
189 
190 #if CONFIG_CYUV_DECODER
191 const FFCodec ff_cyuv_decoder = {
192  .p.name = "cyuv",
193  CODEC_LONG_NAME("Creative YUV (CYUV)"),
194  .p.type = AVMEDIA_TYPE_VIDEO,
195  .p.id = AV_CODEC_ID_CYUV,
196  .priv_data_size = sizeof(CyuvDecodeContext),
199  .p.capabilities = AV_CODEC_CAP_DR1,
200 };
201 #endif
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:119
init
static int init
Definition: av_tx.c:47
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:123
CyuvDecodeContext
Definition: cyuv.c:41
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
cyuv_decode_frame
static int cyuv_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)
Definition: cyuv.c:60
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:298
s
#define s(width, name)
Definition: cbs_vp9.c:256
CyuvDecodeContext::width
int width
Definition: cyuv.c:43
cyuv_decode_init
static av_cold int cyuv_decode_init(AVCodecContext *avctx)
Definition: cyuv.c:46
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:264
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:408
CyuvDecodeContext::avctx
AVCodecContext * avctx
Definition: cyuv.c:42
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1450
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:375
codec_internal.h
ff_cyuv_decoder
const FFCodec ff_cyuv_decoder
AV_CODEC_ID_CYUV
@ AV_CODEC_ID_CYUV
Definition: codec_id.h:78
internal.h
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
ff_aura_decoder
const FFCodec ff_aura_decoder
avcodec.h
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
AV_PIX_FMT_UYVY422
@ AV_PIX_FMT_UYVY422
packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1
Definition: pixfmt.h:81
AVCodecContext
main external API structure.
Definition: avcodec.h:398
CyuvDecodeContext::height
int height
Definition: cyuv.c:43
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
FFALIGN
#define FFALIGN(x, a)
Definition: macros.h:78
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AV_PIX_FMT_YUV411P
@ AV_PIX_FMT_YUV411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:73
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_CODEC_ID_AURA
@ AV_CODEC_ID_AURA
Definition: codec_id.h:175