From 0c251257b57a3916735795f107597e5d457eabd3 Mon Sep 17 00:00:00 2001 From: Derek Buitenhuis Date: Fri, 11 Nov 2011 18:13:35 -0500 Subject: VBLE Decoder Add a decoder for the VBLE Lossless Codec, which still has a cult following. Used to be popular several years ago on doom9. Signed-off-by: Derek Buitenhuis Signed-off-by: Michael Niedermayer --- libavcodec/vble.c | 248 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 248 insertions(+) create mode 100644 libavcodec/vble.c (limited to 'libavcodec/vble.c') diff --git a/libavcodec/vble.c b/libavcodec/vble.c new file mode 100644 index 0000000000..bfc9223e63 --- /dev/null +++ b/libavcodec/vble.c @@ -0,0 +1,248 @@ +/* + * 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 ALT_BITSTREAM_READER_LE + +#include "avcodec.h" +#include "get_bits.h" + +typedef struct { + AVCodecContext *avctx; + + int size; + int flags; + uint8_t *len; + uint8_t *val; +} 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; + + /* Read all the lengths in first */ + for (i = 0; i < ctx->size; i++) { + ctx->len[i] = vble_read_reverse_unary(gb); + + if (ctx->len[i] == UINT8_MAX) + return -1; + } + + /* For any values that have length 0 */ + memset(ctx->val, 0, ctx->size); + + for (i = 0; i < ctx->size; i++) { + /* Check we have enough bits left */ + if (get_bits_left(gb) < ctx->len[i]) + return -1; + + /* get_bits can't take a length of 0 */ + if (ctx->len[i]) + ctx->val[i] = (1 << ctx->len[i]) + get_bits(gb, ctx->len[i]) - 1; + } + + return 0; +} + +static void vble_restore_plane(VBLEContext *ctx, 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; + uint8_t *len = ctx->len + offset; + uint8_t a, b, c; + int stride = pic->linesize[plane]; + int i, j; + + for (i = 0; i < height; i++) { + for (j = 0; j < width; j++) { + dst[j] = (val[j] >> 1) ^ -(val[j] & 1); + + /* Top line and left column are not predicted */ + if (!j) + continue; + + if (!i) { + dst[j] += dst[j - 1]; + continue; + } + + a = dst[j - 1]; + b = dst[j - stride]; + c = a + b - dst[j - 1 - stride]; + dst[j] += mid_pred(a, b, c); + } + dst += stride; + val += width; + len += 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); + + /* 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 = FF_I_TYPE; + + /* Version should always be 1 */ + version = AV_RL32(src); + + if (version != 1) { + av_log(avctx, AV_LOG_ERROR, "Unsupported VBLE Version: %d\n", version); + return AVERROR_INVALIDDATA; + } + + 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, 0, offset, avctx->width, avctx->height); + + /* Chroma */ + if (!(ctx->flags & CODEC_FLAG_GRAY)) { + offset += avctx->width * avctx->height; + vble_restore_plane(ctx, 1, offset, width_uv, height_uv); + + offset += width_uv * height_uv; + vble_restore_plane(ctx, 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->len); + av_freep(&ctx->val); + + return 0; +} + +static av_always_inline int vble_error_close(AVCodecContext *avctx, + const char *message) +{ + av_log(avctx, AV_LOG_ERROR, message); + vble_decode_close(avctx); + return AVERROR(ENOMEM); +} + +static av_cold int vble_decode_init(AVCodecContext *avctx) +{ + VBLEContext *ctx = avctx->priv_data; + + /* Stash for later use */ + ctx->avctx = avctx; + ctx->flags = avctx->flags; + + avctx->pix_fmt = PIX_FMT_YUV420P; + avctx->bits_per_raw_sample = 8; + avctx->coded_frame = avcodec_alloc_frame(); + + if (!avctx->coded_frame) + return vble_error_close(avctx, "Could not allocate frame.\n"); + + ctx->size = avpicture_get_size(avctx->pix_fmt, + avctx->width, avctx->height); + + ctx->len = av_malloc(ctx->size * sizeof(*ctx->len)); + + if (!ctx->len) + return vble_error_close(avctx, "Could not allocate lengths buffer.\n"); + + ctx->val = av_malloc(ctx->size * sizeof(*ctx->val)); + + if (!ctx->val) + return vble_error_close(avctx, "Could not allocate values buffer.\n"); + + return 0; +} + +AVCodec ff_vble_decoder = { + .name = "vble", + .type = AVMEDIA_TYPE_VIDEO, + .id = 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"), +}; -- cgit v1.2.3