libavcodec/jvdec.c

   1 /*
   2  * Bitmap Brothers JV video decoder
   3  * Copyright (c) 2011 Peter Ross <pross@xvid.org>
   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  * Bitmap Brothers JV video decoder
  25  * @author Peter Ross <pross@xvid.org>
  26  */
  27
  28 #include "avcodec.h"
  29 #include "dsputil.h"
  30 #include "get_bits.h"
  31 #include "libavutil/intreadwrite.h"
  32
  33 typedef struct JvContext {
  34     DSPContext dsp;
  35     AVFrame    frame;
  36     uint32_t   palette[AVPALETTE_COUNT];
  37     int        palette_has_changed;
  38 } JvContext;
  39
  40 static av_cold int decode_init(AVCodecContext *avctx)
  41 {
  42     JvContext *s = avctx->priv_data;
  43     avctx->pix_fmt = AV_PIX_FMT_PAL8;
  44     ff_dsputil_init(&s->dsp, avctx);
  45     return 0;
  46 }
  47
  48 /**
  49  * Decode 2x2 block
  50  */
  51 static inline void decode2x2(GetBitContext *gb, uint8_t *dst, int linesize)
  52 {
  53     int i, j, v[2];
  54
  55     switch (get_bits(gb, 2)) {
  56     case 1:
  57         v[0] = get_bits(gb, 8);
  58         for (j = 0; j < 2; j++)
  59             memset(dst + j*linesize, v[0], 2);
  60         break;
  61     case 2:
  62         v[0] = get_bits(gb, 8);
  63         v[1] = get_bits(gb, 8);
  64         for (j = 0; j < 2; j++)
  65             for (i = 0; i < 2; i++)
  66                 dst[j*linesize + i] = v[get_bits1(gb)];
  67         break;
  68     case 3:
  69         for (j = 0; j < 2; j++)
  70             for (i = 0; i < 2; i++)
  71                 dst[j*linesize + i] = get_bits(gb, 8);
  72     }
  73 }
  74
  75 /**
  76  * Decode 4x4 block
  77  */
  78 static inline void decode4x4(GetBitContext *gb, uint8_t *dst, int linesize)
  79 {
  80     int i, j, v[2];
  81
  82     switch (get_bits(gb, 2)) {
  83     case 1:
  84         v[0] = get_bits(gb, 8);
  85         for (j = 0; j < 4; j++)
  86             memset(dst + j*linesize, v[0], 4);
  87         break;
  88     case 2:
  89         v[0] = get_bits(gb, 8);
  90         v[1] = get_bits(gb, 8);
  91         for (j = 2; j >= 0; j -= 2) {
  92             for (i = 0; i < 4; i++)
  93                 dst[j*linesize + i]     = v[get_bits1(gb)];
  94             for (i = 0; i < 4; i++)
  95                 dst[(j+1)*linesize + i] = v[get_bits1(gb)];
  96         }
  97         break;
  98     case 3:
  99         for (j = 0; j < 4; j += 2)
 100             for (i = 0; i < 4; i += 2)
 101                 decode2x2(gb, dst + j*linesize + i, linesize);
 102     }
 103 }
 104
 105 /**
 106  * Decode 8x8 block
 107  */
 108 static inline void decode8x8(GetBitContext *gb, uint8_t *dst, int linesize, DSPContext *dsp)
 109 {
 110     int i, j, v[2];
 111
 112     switch (get_bits(gb, 2)) {
 113     case 1:
 114         v[0] = get_bits(gb, 8);
 115         dsp->fill_block_tab[1](dst, v[0], linesize, 8);
 116         break;
 117     case 2:
 118         v[0] = get_bits(gb, 8);
 119         v[1] = get_bits(gb, 8);
 120         for (j = 7; j >= 0; j--)
 121             for (i = 0; i <  8; i++)
 122                 dst[j*linesize + i] = v[get_bits1(gb)];
 123         break;
 124     case 3:
 125         for (j = 0; j < 8; j += 4)
 126             for (i = 0; i < 8; i += 4)
 127                 decode4x4(gb, dst + j*linesize + i, linesize);
 128     }
 129 }
 130
 131 static int decode_frame(AVCodecContext *avctx,
 132                         void *data, int *got_frame,
 133                         AVPacket *avpkt)
 134 {
 135     JvContext *s           = avctx->priv_data;
 136     int buf_size           = avpkt->size;
 137     const uint8_t *buf     = avpkt->data;
 138     const uint8_t *buf_end = buf + buf_size;
 139     int video_size, video_type, i, j;
 140
 141     video_size = AV_RL32(buf);
 142     video_type = buf[4];
 143     buf += 5;
 144
 145     if (video_size) {
 146         if (avctx->reget_buffer(avctx, &s->frame) < 0) {
 147             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 148             return -1;
 149         }
 150
 151         if (video_type == 0 || video_type == 1) {
 152             GetBitContext gb;
 153             init_get_bits(&gb, buf, 8 * FFMIN(video_size, buf_end - buf));
 154
 155             for (j = 0; j < avctx->height; j += 8)
 156                 for (i = 0; i < avctx->width; i += 8)
 157                     decode8x8(&gb, s->frame.data[0] + j*s->frame.linesize[0] + i,
 158                               s->frame.linesize[0], &s->dsp);
 159
 160             buf += video_size;
 161         } else if (video_type == 2) {
 162             if (buf + 1 <= buf_end) {
 163                 int v = *buf++;
 164                 for (j = 0; j < avctx->height; j++)
 165                     memset(s->frame.data[0] + j*s->frame.linesize[0], v, avctx->width);
 166             }
 167         } else {
 168             av_log(avctx, AV_LOG_WARNING, "unsupported frame type %i\n", video_type);
 169             return AVERROR_INVALIDDATA;
 170         }
 171     }
 172
 173     if (buf < buf_end) {
 174         for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) {
 175             s->palette[i] = AV_RB24(buf) << 2;
 176             buf += 3;
 177         }
 178         s->palette_has_changed = 1;
 179     }
 180
 181     if (video_size) {
 182         s->frame.key_frame           = 1;
 183         s->frame.pict_type           = AV_PICTURE_TYPE_I;
 184         s->frame.palette_has_changed = s->palette_has_changed;
 185         s->palette_has_changed       = 0;
 186         memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
 187
 188         *got_frame = 1;
 189         *(AVFrame*)data = s->frame;
 190     }
 191
 192     return buf_size;
 193 }
 194
 195 static av_cold int decode_close(AVCodecContext *avctx)
 196 {
 197     JvContext *s = avctx->priv_data;
 198
 199     if(s->frame.data[0])
 200         avctx->release_buffer(avctx, &s->frame);
 201
 202     return 0;
 203 }
 204
 205 AVCodec ff_jv_decoder = {
 206     .name           = "jv",
 207     .long_name      = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"),
 208     .type           = AVMEDIA_TYPE_VIDEO,
 209     .id             = AV_CODEC_ID_JV,
 210     .priv_data_size = sizeof(JvContext),
 211     .init           = decode_init,
 212     .close          = decode_close,
 213     .decode         = decode_frame,
 214     .capabilities   = CODEC_CAP_DR1,
 215 };