* VBLE Decoder
* Copyright (c) 2011 Derek Buitenhuis
*
- * This file is part of Libav.
+ * This file is part of FFmpeg.
*
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
DSPContext dsp;
int size;
- uint8_t *val; /* First holds the lengths of vlc symbols and then their values */
+ uint8_t *val; ///< This array first holds the lengths of vlc symbols and then their value.
} VBLEContext;
-static uint8_t vble_read_reverse_unary(GetBitContext *gb)
-{
- /* At most we need to read 9 bits total to get indices up to 8 */
- uint8_t val = show_bits(gb, 8);
-
- if (val) {
- val = 7 - av_log2_16bit(av_reverse[val]);
- skip_bits(gb, val + 1);
- return val;
- } else {
- skip_bits(gb, 8);
- if (get_bits1(gb))
- return 8;
- }
-
- /* Return something larger than 8 on error */
- return UINT8_MAX;
-}
-
static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
{
int i;
+ int allbits = 0;
+ static const uint8_t LUT[256] = {
+ 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,
+ 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,
+ 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,
+ 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,
+ 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,
+ 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,
+ 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,
+ 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,
+ };
/* Read all the lengths in first */
for (i = 0; i < ctx->size; i++) {
- ctx->val[i] = vble_read_reverse_unary(gb);
-
- if (ctx->val[i] == UINT8_MAX)
- return -1;
- }
-
- for (i = 0; i < ctx->size; i++) {
- /* Check we have enough bits left */
- if (get_bits_left(gb) < ctx->val[i])
- return -1;
-
- /* get_bits can't take a length of 0 */
- if (ctx->val[i])
- ctx->val[i] = (1 << ctx->val[i]) + get_bits(gb, ctx->val[i]) - 1;
+ /* At most we need to read 9 bits total to get indices up to 8 */
+ int val = show_bits(gb, 8);
+
+ // read reverse unary
+ if (val) {
+ val = LUT[val];
+ skip_bits(gb, val + 1);
+ ctx->val[i] = val;
+ } else {
+ skip_bits(gb, 8);
+ if (!get_bits1(gb))
+ return -1;
+ ctx->val[i] = 8;
+ }
+ allbits += ctx->val[i];
}
+ /* Check we have enough bits left */
+ if (get_bits_left(gb) < allbits)
+ return -1;
return 0;
}
-static void vble_restore_plane(VBLEContext *ctx, int plane, int offset,
- int width, int height)
+static void vble_restore_plane(VBLEContext *ctx, GetBitContext *gb, int plane,
+ int offset, int width, int height)
{
AVFrame *pic = ctx->avctx->coded_frame;
uint8_t *dst = pic->data[plane];
int i, j, left, left_top;
for (i = 0; i < height; i++) {
- for (j = 0; j < width; j++)
- val[j] = (val[j] >> 1) ^ -(val[j] & 1);
-
+ for (j = 0; j < width; j++) {
+ /* get_bits can't take a length of 0 */
+ if (val[j]) {
+ int v = (1 << val[j]) + get_bits(gb, val[j]) - 1;
+ val[j] = (v >> 1) ^ -(v & 1);
+ }
+ }
if (i) {
left = 0;
left_top = dst[-stride];
- ctx->dsp.add_hfyu_median_prediction(dst, dst-stride, val,
- width, &left, &left_top);
+ ctx->dsp.add_hfyu_median_prediction(dst, dst-stride, val, width, &left, &left_top);
} else {
dst[0] = val[0];
for (j = 1; j < width; j++)
/* Set flags */
pic->key_frame = 1;
- pic->pict_type = FF_I_TYPE;
+ pic->pict_type = AV_PICTURE_TYPE_I;
/* Version should always be 1 */
version = AV_RL32(src);
}
/* Restore planes. Should be almost identical to Huffyuv's. */
- vble_restore_plane(ctx, 0, offset, avctx->width, avctx->height);
+ vble_restore_plane(ctx, &gb, 0, offset, avctx->width, avctx->height);
/* Chroma */
if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
offset += avctx->width * avctx->height;
- vble_restore_plane(ctx, 1, offset, width_uv, height_uv);
+ vble_restore_plane(ctx, &gb, 1, offset, width_uv, height_uv);
offset += width_uv * height_uv;
- vble_restore_plane(ctx, 2, offset, width_uv, height_uv);
+ vble_restore_plane(ctx, &gb, 2, offset, width_uv, height_uv);
}
*data_size = sizeof(AVFrame);
projects / ffmpeg / blobdiff