/* * 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 "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, GetBitContext *gb, int plane, int offset, int width, int height) { AVFrame *pic = ctx->avctx->coded_frame; 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 *data_size, AVPacket *avpkt) { VBLEContext *ctx = avctx->priv_data; AVFrame *pic = avctx->coded_frame; GetBitContext gb; const uint8_t *src = avpkt->data; int version; int offset = 0; int width_uv = avctx->width / 2, height_uv = avctx->height / 2; pic->reference = 0; /* Clear buffer if need be */ if (pic->data[0]) avctx->release_buffer(avctx, pic); 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 (avctx->get_buffer(avctx, pic) < 0) { av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n"); return AVERROR(ENOMEM); } /* 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, &gb, 0, offset, avctx->width, avctx->height); /* Chroma */ if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) { offset += avctx->width * avctx->height; vble_restore_plane(ctx, &gb, 1, offset, width_uv, height_uv); offset += width_uv * height_uv; vble_restore_plane(ctx, &gb, 2, offset, width_uv, height_uv); } *data_size = sizeof(AVFrame); *(AVFrame *)data = *pic; return avpkt->size; } static av_cold int vble_decode_close(AVCodecContext *avctx) { VBLEContext *ctx = avctx->priv_data; AVFrame *pic = avctx->coded_frame; if (pic->data[0]) avctx->release_buffer(avctx, pic); av_freep(&avctx->coded_frame); 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; avctx->coded_frame = avcodec_alloc_frame(); if (!avctx->coded_frame) { av_log(avctx, AV_LOG_ERROR, "Could not allocate frame.\n"); return AVERROR(ENOMEM); } 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"), };