diff options
Diffstat (limited to 'ffmpeg/libavcodec/vble.c')
| -rw-r--r-- | ffmpeg/libavcodec/vble.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/vble.c b/ffmpeg/libavcodec/vble.c new file mode 100644 index 0000000..cbb2ffc --- /dev/null +++ b/ffmpeg/libavcodec/vble.c @@ -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 + */ + +#define BITSTREAM_READER_LE + +#include "avcodec.h" +#include "dsputil.h" +#include "get_bits.h" +#include "internal.h" +#include "mathops.h" + +typedef struct { + AVCodecContext *avctx; + DSPContext dsp; + + int size; + uint8_t *val; ///< This array first holds the lengths of vlc symbols and then their value. +} VBLEContext; + +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++) { + /* 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, 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; + } +} + +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; + + 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; + + /* Version should always be 1 */ + version = AV_RL32(src); + + if (version != 1) + av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version); + + init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8); + + /* Unpack */ + if (vble_unpack(ctx, &gb) < 0) { + av_log(avctx, AV_LOG_ERROR, "Invalid Code\n"); + return AVERROR_INVALIDDATA; + } + + /* Restore planes. Should be almost identical to Huffyuv's. */ + vble_restore_plane(ctx, pic, &gb, 0, offset, avctx->width, avctx->height); + + /* 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); + + offset += width_uv * height_uv; + vble_restore_plane(ctx, pic, &gb, 2, offset, width_uv, height_uv); + } + + *got_frame = 1; + + return avpkt->size; +} + +static av_cold int vble_decode_close(AVCodecContext *avctx) +{ + VBLEContext *ctx = avctx->priv_data; + av_freep(&ctx->val); + + return 0; +} + +static av_cold int vble_decode_init(AVCodecContext *avctx) +{ + VBLEContext *ctx = avctx->priv_data; + + /* Stash for later use */ + ctx->avctx = avctx; + ff_dsputil_init(&ctx->dsp, avctx); + + avctx->pix_fmt = AV_PIX_FMT_YUV420P; + avctx->bits_per_raw_sample = 8; + + ctx->size = avpicture_get_size(avctx->pix_fmt, + avctx->width, avctx->height); + + ctx->val = av_malloc(ctx->size * sizeof(*ctx->val)); + + if (!ctx->val) { + av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n"); + vble_decode_close(avctx); + return AVERROR(ENOMEM); + } + + return 0; +} + +AVCodec ff_vble_decoder = { + .name = "vble", + .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, + .long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"), +}; |