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 "libavutil/intreadwrite.h"
  29
  30 #include "avcodec.h"
  31 #include "bitstream.h"
  32 #include "blockdsp.h"
  33 #include "internal.h"
  34
  35 typedef struct JvContext {
  36     BlockDSPContext bdsp;
  37     AVFrame   *frame;
  38     uint32_t   palette[AVPALETTE_COUNT];
  39     int        palette_has_changed;
  40 } JvContext;
  41
  42 static av_cold int decode_init(AVCodecContext *avctx)
  43 {
  44     JvContext *s = avctx->priv_data;
  45
  46     if (!avctx->width || !avctx->height ||
  47         (avctx->width & 7) || (avctx->height & 7)) {
  48         av_log(avctx, AV_LOG_ERROR, "Invalid video dimensions: %dx%d\n",
  49                avctx->width, avctx->height);
  50         return AVERROR(EINVAL);
  51     }
  52
  53     s->frame = av_frame_alloc();
  54     if (!s->frame)
  55         return AVERROR(ENOMEM);
  56
  57     avctx->pix_fmt = AV_PIX_FMT_PAL8;
  58     ff_blockdsp_init(&s->bdsp);
  59     return 0;
  60 }
  61
  62 /**
  63  * Decode 2x2 block
  64  */
  65 static inline void decode2x2(BitstreamContext *bc, uint8_t *dst, int linesize)
  66 {
  67     int i, j, v[2];
  68
  69     switch (bitstream_read(bc, 2)) {
  70     case 1:
  71         v[0] = bitstream_read(bc, 8);
  72         for (j = 0; j < 2; j++)
  73             memset(dst + j * linesize, v[0], 2);
  74         break;
  75     case 2:
  76         v[0] = bitstream_read(bc, 8);
  77         v[1] = bitstream_read(bc, 8);
  78         for (j = 0; j < 2; j++)
  79             for (i = 0; i < 2; i++)
  80                 dst[j * linesize + i] = v[bitstream_read_bit(bc)];
  81         break;
  82     case 3:
  83         for (j = 0; j < 2; j++)
  84             for (i = 0; i < 2; i++)
  85                 dst[j * linesize + i] = bitstream_read(bc, 8);
  86     }
  87 }
  88
  89 /**
  90  * Decode 4x4 block
  91  */
  92 static inline void decode4x4(BitstreamContext *bc, uint8_t *dst, int linesize)
  93 {
  94     int i, j, v[2];
  95
  96     switch (bitstream_read(bc, 2)) {
  97     case 1:
  98         v[0] = bitstream_read(bc, 8);
  99         for (j = 0; j < 4; j++)
 100             memset(dst + j * linesize, v[0], 4);
 101         break;
 102     case 2:
 103         v[0] = bitstream_read(bc, 8);
 104         v[1] = bitstream_read(bc, 8);
 105         for (j = 2; j >= 0; j -= 2) {
 106             for (i = 0; i < 4; i++)
 107                 dst[j * linesize + i] = v[bitstream_read_bit(bc)];
 108             for (i = 0; i < 4; i++)
 109                 dst[(j + 1) * linesize + i] = v[bitstream_read_bit(bc)];
 110         }
 111         break;
 112     case 3:
 113         for (j = 0; j < 4; j += 2)
 114             for (i = 0; i < 4; i += 2)
 115                 decode2x2(bc, dst + j * linesize + i, linesize);
 116     }
 117 }
 118
 119 /**
 120  * Decode 8x8 block
 121  */
 122 static inline void decode8x8(BitstreamContext *bc, uint8_t *dst, int linesize,
 123                              BlockDSPContext *bdsp)
 124 {
 125     int i, j, v[2];
 126
 127     switch (bitstream_read(bc, 2)) {
 128     case 1:
 129         v[0] = bitstream_read(bc, 8);
 130         bdsp->fill_block_tab[1](dst, v[0], linesize, 8);
 131         break;
 132     case 2:
 133         v[0] = bitstream_read(bc, 8);
 134         v[1] = bitstream_read(bc, 8);
 135         for (j = 7; j >= 0; j--)
 136             for (i = 0; i < 8; i++)
 137                 dst[j * linesize + i] = v[bitstream_read_bit(bc)];
 138         break;
 139     case 3:
 140         for (j = 0; j < 8; j += 4)
 141             for (i = 0; i < 8; i += 4)
 142                 decode4x4(bc, dst + j * linesize + i, linesize);
 143     }
 144 }
 145
 146 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 147                         AVPacket *avpkt)
 148 {
 149     JvContext *s = avctx->priv_data;
 150     int buf_size = avpkt->size;
 151     const uint8_t *buf = avpkt->data;
 152     const uint8_t *buf_end = buf + buf_size;
 153     int video_size, video_type, i, j, ret;
 154
 155     video_size = AV_RL32(buf);
 156     video_type = buf[4];
 157     buf += 5;
 158
 159     if (video_size) {
 160         if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
 161             av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 162             return ret;
 163         }
 164
 165         if (video_type == 0 || video_type == 1) {
 166             BitstreamContext bc;
 167             bitstream_init8(&bc, buf, FFMIN(video_size, buf_end - buf));
 168
 169             for (j = 0; j < avctx->height; j += 8)
 170                 for (i = 0; i < avctx->width; i += 8)
 171                     decode8x8(&bc,
 172                               s->frame->data[0] + j * s->frame->linesize[0] + i,
 173                               s->frame->linesize[0], &s->bdsp);
 174
 175             buf += video_size;
 176         } else if (video_type == 2) {
 177             if (buf + 1 <= buf_end) {
 178                 int v = *buf++;
 179                 for (j = 0; j < avctx->height; j++)
 180                     memset(s->frame->data[0] + j * s->frame->linesize[0],
 181                            v, avctx->width);
 182             }
 183         } else {
 184             av_log(avctx, AV_LOG_WARNING,
 185                    "unsupported frame type %i\n", video_type);
 186             return AVERROR_INVALIDDATA;
 187         }
 188     }
 189
 190     if (buf < buf_end) {
 191         for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) {
 192             s->palette[i] = AV_RB24(buf) << 2;
 193             buf += 3;
 194         }
 195         s->palette_has_changed = 1;
 196     }
 197
 198     if (video_size) {
 199         s->frame->key_frame           = 1;
 200         s->frame->pict_type           = AV_PICTURE_TYPE_I;
 201         s->frame->palette_has_changed = s->palette_has_changed;
 202         s->palette_has_changed        = 0;
 203         memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
 204
 205         if ((ret = av_frame_ref(data, s->frame)) < 0)
 206             return ret;
 207         *got_frame = 1;
 208     }
 209
 210     return buf_size;
 211 }
 212
 213 static av_cold int decode_close(AVCodecContext *avctx)
 214 {
 215     JvContext *s = avctx->priv_data;
 216
 217     av_frame_free(&s->frame);
 218
 219     return 0;
 220 }
 221
 222 AVCodec ff_jv_decoder = {
 223     .name           = "jv",
 224     .long_name      = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"),
 225     .type           = AVMEDIA_TYPE_VIDEO,
 226     .id             = AV_CODEC_ID_JV,
 227     .priv_data_size = sizeof(JvContext),
 228     .init           = decode_init,
 229     .close          = decode_close,
 230     .decode         = decode_frame,
 231     .capabilities   = AV_CODEC_CAP_DR1,
 232 };