0,0 → 1,213 |
/* |
* VBLE Decoder |
* Copyright (c) 2011 Derek Buitenhuis |
* |
* This file is part of FFmpeg. |
* |
* 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. |
* |
* 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 FFmpeg; if not, write to the Free Software |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
*/ |
|
/** |
* @file |
* VBLE Decoder |
*/ |
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#define BITSTREAM_READER_LE |
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#include "avcodec.h" |
#include "dsputil.h" |
#include "get_bits.h" |
#include "internal.h" |
#include "mathops.h" |
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typedef struct { |
AVCodecContext *avctx; |
DSPContext dsp; |
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int size; |
uint8_t *val; ///< This array first holds the lengths of vlc symbols and then their value. |
} VBLEContext; |
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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, |
}; |
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/* Read all the lengths in first */ |
for (i = 0; i < ctx->size; i++) { |
/* 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]; |
} |
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/* Check we have enough bits left */ |
if (get_bits_left(gb) < allbits) |
return -1; |
return 0; |
} |
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static void vble_restore_plane(VBLEContext *ctx, AVFrame *pic, |
GetBitContext *gb, int plane, |
int offset, int width, int height) |
{ |
uint8_t *dst = pic->data[plane]; |
uint8_t *val = ctx->val + offset; |
int stride = pic->linesize[plane]; |
int i, j, left, left_top; |
|
for (i = 0; i < height; i++) { |
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); |
} else { |
dst[0] = val[0]; |
for (j = 1; j < width; j++) |
dst[j] = val[j] + dst[j - 1]; |
} |
dst += stride; |
val += width; |
} |
} |
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static int vble_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
AVPacket *avpkt) |
{ |
VBLEContext *ctx = avctx->priv_data; |
AVFrame *pic = data; |
GetBitContext gb; |
const uint8_t *src = avpkt->data; |
int version; |
int offset = 0; |
int width_uv = avctx->width / 2, height_uv = avctx->height / 2; |
int ret; |
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if (avpkt->size < 4 || avpkt->size - 4 > INT_MAX/8) { |
av_log(avctx, AV_LOG_ERROR, "Invalid packet size\n"); |
return AVERROR_INVALIDDATA; |
} |
|
/* Allocate buffer */ |
if ((ret = ff_get_buffer(avctx, pic, 0)) < 0) |
return ret; |
|
/* Set flags */ |
pic->key_frame = 1; |
pic->pict_type = AV_PICTURE_TYPE_I; |
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/* Version should always be 1 */ |
version = AV_RL32(src); |
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if (version != 1) |
av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version); |
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init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8); |
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/* Unpack */ |
if (vble_unpack(ctx, &gb) < 0) { |
av_log(avctx, AV_LOG_ERROR, "Invalid Code\n"); |
return AVERROR_INVALIDDATA; |
} |
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/* Restore planes. Should be almost identical to Huffyuv's. */ |
vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height); |
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/* Chroma */ |
if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) { |
offset += avctx->width * avctx->height; |
vble_restore_plane(ctx, pic, &gb, 1, offset, width_uv, height_uv); |
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offset += width_uv * height_uv; |
vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv); |
} |
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*got_frame = 1; |
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return avpkt->size; |
} |
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static av_cold int vble_decode_close(AVCodecContext *avctx) |
{ |
VBLEContext *ctx = avctx->priv_data; |
av_freep(&ctx->val); |
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return 0; |
} |
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static av_cold int vble_decode_init(AVCodecContext *avctx) |
{ |
VBLEContext *ctx = avctx->priv_data; |
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/* Stash for later use */ |
ctx->avctx = avctx; |
ff_dsputil_init(&ctx->dsp, avctx); |
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avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
avctx->bits_per_raw_sample = 8; |
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ctx->size = avpicture_get_size(avctx->pix_fmt, |
avctx->width, avctx->height); |
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ctx->val = av_malloc(ctx->size * sizeof(*ctx->val)); |
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if (!ctx->val) { |
av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n"); |
vble_decode_close(avctx); |
return AVERROR(ENOMEM); |
} |
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return 0; |
} |
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AVCodec ff_vble_decoder = { |
.name = "vble", |
.long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"), |
.type = AVMEDIA_TYPE_VIDEO, |
.id = AV_CODEC_ID_VBLE, |
.priv_data_size = sizeof(VBLEContext), |
.init = vble_decode_init, |
.close = vble_decode_close, |
.decode = vble_decode_frame, |
.capabilities = CODEC_CAP_DR1, |
}; |