1 /*
2 * ATI VCR1 codec
3 * Copyright (c) 2003 Michael Niedermayer
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 * ATI VCR1 codec
25 */
26
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "libavutil/avassert.h"
30 #include "libavutil/internal.h"
31
32 typedef struct VCR1Context {
33 int delta[16];
34 int offset[4];
35 } VCR1Context;
36
vcr1_decode_init(AVCodecContext * avctx)37 static av_cold int vcr1_decode_init(AVCodecContext *avctx)
38 {
39 avctx->pix_fmt = AV_PIX_FMT_YUV410P;
40
41 if (avctx->width % 8 || avctx->height%4) {
42 avpriv_request_sample(avctx, "odd dimensions (%d x %d) support", avctx->width, avctx->height);
43 return AVERROR_INVALIDDATA;
44 }
45
46 return 0;
47 }
48
vcr1_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)49 static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
50 int *got_frame, AVPacket *avpkt)
51 {
52 VCR1Context *const a = avctx->priv_data;
53 AVFrame *const p = data;
54 const uint8_t *bytestream = avpkt->data;
55 const uint8_t *bytestream_end = bytestream + avpkt->size;
56 int i, x, y, ret;
57
58 if(avpkt->size < 32 + avctx->height + avctx->width*avctx->height*5/8){
59 av_log(avctx, AV_LOG_ERROR, "Insufficient input data. %d < %d\n", avpkt->size , 32 + avctx->height + avctx->width*avctx->height*5/8);
60 return AVERROR(EINVAL);
61 }
62
63 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
64 return ret;
65 p->pict_type = AV_PICTURE_TYPE_I;
66 p->key_frame = 1;
67
68 for (i = 0; i < 16; i++) {
69 a->delta[i] = *bytestream++;
70 bytestream++;
71 }
72
73 for (y = 0; y < avctx->height; y++) {
74 int offset;
75 uint8_t *luma = &p->data[0][y * p->linesize[0]];
76
77 if ((y & 3) == 0) {
78 uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
79 uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];
80
81 av_assert0 (bytestream_end - bytestream >= 4 + avctx->width);
82
83 for (i = 0; i < 4; i++)
84 a->offset[i] = *bytestream++;
85
86 offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
87 for (x = 0; x < avctx->width; x += 4) {
88 luma[0] = offset += a->delta[bytestream[2] & 0xF];
89 luma[1] = offset += a->delta[bytestream[2] >> 4];
90 luma[2] = offset += a->delta[bytestream[0] & 0xF];
91 luma[3] = offset += a->delta[bytestream[0] >> 4];
92 luma += 4;
93
94 *cb++ = bytestream[3];
95 *cr++ = bytestream[1];
96
97 bytestream += 4;
98 }
99 } else {
100 av_assert0 (bytestream_end - bytestream >= avctx->width / 2);
101
102 offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
103
104 for (x = 0; x < avctx->width; x += 8) {
105 luma[0] = offset += a->delta[bytestream[2] & 0xF];
106 luma[1] = offset += a->delta[bytestream[2] >> 4];
107 luma[2] = offset += a->delta[bytestream[3] & 0xF];
108 luma[3] = offset += a->delta[bytestream[3] >> 4];
109 luma[4] = offset += a->delta[bytestream[0] & 0xF];
110 luma[5] = offset += a->delta[bytestream[0] >> 4];
111 luma[6] = offset += a->delta[bytestream[1] & 0xF];
112 luma[7] = offset += a->delta[bytestream[1] >> 4];
113 luma += 8;
114 bytestream += 4;
115 }
116 }
117 }
118
119 *got_frame = 1;
120
121 return bytestream - avpkt->data;
122 }
123
124 AVCodec ff_vcr1_decoder = {
125 .name = "vcr1",
126 .long_name = NULL_IF_CONFIG_SMALL("ATI VCR1"),
127 .type = AVMEDIA_TYPE_VIDEO,
128 .id = AV_CODEC_ID_VCR1,
129 .priv_data_size = sizeof(VCR1Context),
130 .init = vcr1_decode_init,
131 .decode = vcr1_decode_frame,
132 .capabilities = AV_CODEC_CAP_DR1,
133 };
134