ffmpeg/libavcodec/vble.c

   1 /*
   2  * VBLE Decoder
   3  * Copyright (c) 2011 Derek Buitenhuis
   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  * VBLE Decoder
  25  */
  26
  27 #define BITSTREAM_READER_LE
  28
  29 #include "avcodec.h"
  30 #include "get_bits.h"
  31 #include "huffyuvdsp.h"
  32 #include "internal.h"
  33 #include "mathops.h"
  34
  35 typedef struct {
  36     AVCodecContext *avctx;
  37     HuffYUVDSPContext hdsp;
  38
  39     int            size;
  40     uint8_t        *val; ///< This array first holds the lengths of vlc symbols and then their value.
  41 } VBLEContext;
  42
  43 static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
  44 {
  45     int i;
  46     int allbits = 0;
  47     static const uint8_t LUT[256] = {
  48         8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  49         5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  50         6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  51         5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  52         7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  53         5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  54         6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  55         5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
  56     };
  57
  58     /* Read all the lengths in first */
  59     for (i = 0; i < ctx->size; i++) {
  60         /* At most we need to read 9 bits total to get indices up to 8 */
  61         int val = show_bits(gb, 8);
  62
  63         // read reverse unary
  64         if (val) {
  65             val = LUT[val];
  66             skip_bits(gb, val + 1);
  67             ctx->val[i] = val;
  68         } else {
  69             skip_bits(gb, 8);
  70             if (!get_bits1(gb))
  71                 return -1;
  72             ctx->val[i] = 8;
  73         }
  74         allbits += ctx->val[i];
  75     }
  76
  77     /* Check we have enough bits left */
  78     if (get_bits_left(gb) < allbits)
  79         return -1;
  80     return 0;
  81 }
  82
  83 static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic,
  84                                GetBitContext *gb, int plane,
  85                                int offset, int width, int height)
  86 {
  87     uint8_t *dst = pic->data[plane];
  88     uint8_t *val = ctx->val + offset;
  89     int stride = pic->linesize[plane];
  90     int i, j, left, left_top;
  91
  92     for (i = 0; i < height; i++) {
  93         for (j = 0; j < width; j++) {
  94             /* get_bits can't take a length of 0 */
  95             if (val[j]) {
  96                 int v = (1 << val[j]) + get_bits(gb, val[j]) - 1;
  97                 val[j] = (v >> 1) ^ -(v & 1);
  98             }
  99         }
 100         if (i) {
 101             left = 0;
 102             left_top = dst[-stride];
 103             ctx->hdsp.add_hfyu_median_pred(dst, dst - stride, val,
 104                                            width, &left, &left_top);
 105         } else {
 106             dst[0] = val[0];
 107             for (j = 1; j < width; j++)
 108                 dst[j] = val[j] + dst[j - 1];
 109         }
 110         dst += stride;
 111         val += width;
 112     }
 113 }
 114
 115 static int vble_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 116                              AVPacket *avpkt)
 117 {
 118     VBLEContext *ctx = avctx->priv_data;
 119     AVFrame *pic     = data;
 120     GetBitContext gb;
 121     const uint8_t *src = avpkt->data;
 122     int version;
 123     int offset = 0;
 124     int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
 125     int ret;
 126
 127     if (avpkt->size < 4 || avpkt->size - 4 > INT_MAX/8) {
 128         av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n");
 129         return AVERROR_INVALIDDATA;
 130     }
 131
 132     /* Allocate buffer */
 133     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
 134         return ret;
 135
 136     /* Set flags */
 137     pic->key_frame = 1;
 138     pic->pict_type = AV_PICTURE_TYPE_I;
 139
 140     /* Version should always be 1 */
 141     version = AV_RL32(src);
 142
 143     if (version != 1)
 144         av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
 145
 146     init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
 147
 148     /* Unpack */
 149     if (vble_unpack(ctx, &gb) < 0) {
 150         av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
 151         return AVERROR_INVALIDDATA;
 152     }
 153
 154     /* Restore planes. Should be almost identical to Huffyuv's. */
 155     vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height);
 156
 157     /* Chroma */
 158     if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
 159         offset += avctx->width * avctx->height;
 160         vble_restore_plane(ctx, pic, &gb, 1, offset, width_uv, height_uv);
 161
 162         offset += width_uv * height_uv;
 163         vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv);
 164     }
 165
 166     *got_frame       = 1;
 167
 168     return avpkt->size;
 169 }
 170
 171 static av_cold int vble_decode_close(AVCodecContext *avctx)
 172 {
 173     VBLEContext *ctx = avctx->priv_data;
 174     av_freep(&ctx->val);
 175
 176     return 0;
 177 }
 178
 179 static av_cold int vble_decode_init(AVCodecContext *avctx)
 180 {
 181     VBLEContext *ctx = avctx->priv_data;
 182
 183     /* Stash for later use */
 184     ctx->avctx = avctx;
 185     ff_huffyuvdsp_init(&ctx->hdsp);
 186
 187     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
 188     avctx->bits_per_raw_sample = 8;
 189
 190     ctx->size = avpicture_get_size(avctx->pix_fmt,
 191                                    avctx->width, avctx->height);
 192
 193     ctx->val = av_malloc_array(ctx->size, sizeof(*ctx->val));
 194
 195     if (!ctx->val) {
 196         av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
 197         vble_decode_close(avctx);
 198         return AVERROR(ENOMEM);
 199     }
 200
 201     return 0;
 202 }
 203
 204 AVCodec ff_vble_decoder = {
 205     .name           = "vble",
 206     .long_name      = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
 207     .type           = AVMEDIA_TYPE_VIDEO,
 208     .id             = AV_CODEC_ID_VBLE,
 209     .priv_data_size = sizeof(VBLEContext),
 210     .init           = vble_decode_init,
 211     .close          = vble_decode_close,
 212     .decode         = vble_decode_frame,
 213     .capabilities   = CODEC_CAP_DR1,
 214 };