libavcodec/vcr1.c

   1 /*
   2  * ATI VCR1 codec
   3  * Copyright (c) 2003 Michael Niedermayer
   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
  22 /**
  23  * @file
  24  * ATI VCR1 codec
  25  */
  26
  27 #include "avcodec.h"
  28 #include "dsputil.h"
  29 #include "internal.h"
  30 #include "libavutil/internal.h"
  31
  32 typedef struct VCR1Context {
  33     AVFrame picture;
  34     int delta[16];
  35     int offset[4];
  36 } VCR1Context;
  37
  38 static av_cold int vcr1_common_init(AVCodecContext *avctx)
  39 {
  40     VCR1Context *const a = avctx->priv_data;
  41
  42     avctx->coded_frame = &a->picture;
  43
  44     return 0;
  45 }
  46
  47 static av_cold int vcr1_decode_init(AVCodecContext *avctx)
  48 {
  49     vcr1_common_init(avctx);
  50
  51     avctx->pix_fmt = AV_PIX_FMT_YUV410P;
  52
  53     return 0;
  54 }
  55
  56 static av_cold int vcr1_decode_end(AVCodecContext *avctx)
  57 {
  58     VCR1Context *s = avctx->priv_data;
  59
  60     if (s->picture.data[0])
  61         avctx->release_buffer(avctx, &s->picture);
  62
  63     return 0;
  64 }
  65
  66 static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
  67                              int *got_frame, AVPacket *avpkt)
  68 {
  69     const uint8_t *buf        = avpkt->data;
  70     int buf_size              = avpkt->size;
  71     VCR1Context *const a      = avctx->priv_data;
  72     AVFrame *picture          = data;
  73     AVFrame *const p          = &a->picture;
  74     const uint8_t *bytestream = buf;
  75     int i, x, y, ret;
  76
  77     if (p->data[0])
  78         avctx->release_buffer(avctx, p);
  79
  80     p->reference = 0;
  81     if ((ret = ff_get_buffer(avctx, p)) < 0) {
  82         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  83         return ret;
  84     }
  85     p->pict_type = AV_PICTURE_TYPE_I;
  86     p->key_frame = 1;
  87
  88     for (i = 0; i < 16; i++) {
  89         a->delta[i] = *bytestream++;
  90         bytestream++;
  91     }
  92
  93     for (y = 0; y < avctx->height; y++) {
  94         int offset;
  95         uint8_t *luma = &a->picture.data[0][y * a->picture.linesize[0]];
  96
  97         if ((y & 3) == 0) {
  98             uint8_t *cb = &a->picture.data[1][(y >> 2) * a->picture.linesize[1]];
  99             uint8_t *cr = &a->picture.data[2][(y >> 2) * a->picture.linesize[2]];
 100
 101             for (i = 0; i < 4; i++)
 102                 a->offset[i] = *bytestream++;
 103
 104             offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
 105             for (x = 0; x < avctx->width; x += 4) {
 106                 luma[0]     = offset += a->delta[bytestream[2] & 0xF];
 107                 luma[1]     = offset += a->delta[bytestream[2] >>  4];
 108                 luma[2]     = offset += a->delta[bytestream[0] & 0xF];
 109                 luma[3]     = offset += a->delta[bytestream[0] >>  4];
 110                 luma       += 4;
 111
 112                 *cb++       = bytestream[3];
 113                 *cr++       = bytestream[1];
 114
 115                 bytestream += 4;
 116             }
 117         } else {
 118             offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
 119
 120             for (x = 0; x < avctx->width; x += 8) {
 121                 luma[0]     = offset += a->delta[bytestream[2] & 0xF];
 122                 luma[1]     = offset += a->delta[bytestream[2] >>  4];
 123                 luma[2]     = offset += a->delta[bytestream[3] & 0xF];
 124                 luma[3]     = offset += a->delta[bytestream[3] >>  4];
 125                 luma[4]     = offset += a->delta[bytestream[0] & 0xF];
 126                 luma[5]     = offset += a->delta[bytestream[0] >>  4];
 127                 luma[6]     = offset += a->delta[bytestream[1] & 0xF];
 128                 luma[7]     = offset += a->delta[bytestream[1] >>  4];
 129                 luma       += 8;
 130                 bytestream += 4;
 131             }
 132         }
 133     }
 134
 135     *picture   = a->picture;
 136     *got_frame = 1;
 137
 138     return buf_size;
 139 }
 140
 141 AVCodec ff_vcr1_decoder = {
 142     .name           = "vcr1",
 143     .type           = AVMEDIA_TYPE_VIDEO,
 144     .id             = AV_CODEC_ID_VCR1,
 145     .priv_data_size = sizeof(VCR1Context),
 146     .init           = vcr1_decode_init,
 147     .close          = vcr1_decode_end,
 148     .decode         = vcr1_decode_frame,
 149     .capabilities   = CODEC_CAP_DR1,
 150     .long_name      = NULL_IF_CONFIG_SMALL("ATI VCR1"),
 151 };