mirror of https://github.com/FFmpeg/FFmpeg.git
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 <derek.buitenhuis@gmail.com> Signed-off-by: Martin Storsjö <martin@martin.st>pull/2/head
Derek Buitenhuis
13 years ago
committed by
Martin Storsjö
parent
b656c4d08e
commit
c433a3f9a5
8 changed files with 255 additions and 1 deletions
@ -0,0 +1,248 @@ |
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/*
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* VBLE Decoder |
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* Copyright (c) 2011 Derek Buitenhuis |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/**
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* @file |
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* VBLE Decoder |
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*/ |
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#define ALT_BITSTREAM_READER_LE |
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#include "avcodec.h" |
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#include "get_bits.h" |
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typedef struct { |
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AVCodecContext *avctx; |
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int size; |
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int flags; |
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uint8_t *len; |
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uint8_t *val; |
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} VBLEContext; |
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static uint8_t vble_read_reverse_unary(GetBitContext *gb) |
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{ |
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/* At most we need to read 9 bits total to get indices up to 8 */ |
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uint8_t val = show_bits(gb, 8); |
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if (val) { |
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val = 7 - av_log2_16bit(av_reverse[val]); |
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skip_bits(gb, val + 1); |
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return val; |
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} else { |
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skip_bits(gb, 8); |
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if (get_bits1(gb)) |
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return 8; |
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} |
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/* Return something larger than 8 on error */ |
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return UINT8_MAX; |
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} |
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static int vble_unpack(VBLEContext *ctx, GetBitContext *gb) |
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{ |
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int i; |
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/* Read all the lengths in first */ |
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for (i = 0; i < ctx->size; i++) { |
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ctx->len[i] = vble_read_reverse_unary(gb); |
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if (ctx->len[i] == UINT8_MAX) |
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return -1; |
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} |
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/* For any values that have length 0 */ |
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memset(ctx->val, 0, ctx->size); |
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for (i = 0; i < ctx->size; i++) { |
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/* Check we have enough bits left */ |
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if (get_bits_left(gb) < ctx->len[i]) |
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return -1; |
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/* get_bits can't take a length of 0 */ |
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if (ctx->len[i]) |
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ctx->val[i] = (1 << ctx->len[i]) + get_bits(gb, ctx->len[i]) - 1; |
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} |
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return 0; |
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} |
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static void vble_restore_plane(VBLEContext *ctx, int plane, int offset, |
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int width, int height) |
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{ |
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AVFrame *pic = ctx->avctx->coded_frame; |
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uint8_t *dst = pic->data[plane]; |
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uint8_t *val = ctx->val + offset; |
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uint8_t *len = ctx->len + offset; |
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uint8_t a, b, c; |
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int stride = pic->linesize[plane]; |
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int i, j; |
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for (i = 0; i < height; i++) { |
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for (j = 0; j < width; j++) { |
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dst[j] = (val[j] >> 1) ^ -(val[j] & 1); |
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/* Top line and left column are not predicted */ |
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if (!j) |
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continue; |
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if (!i) { |
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dst[j] += dst[j - 1]; |
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continue; |
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} |
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a = dst[j - 1]; |
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b = dst[j - stride]; |
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c = a + b - dst[j - 1 - stride]; |
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dst[j] += mid_pred(a, b, c); |
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} |
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dst += stride; |
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val += width; |
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len += width; |
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} |
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} |
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static int vble_decode_frame(AVCodecContext *avctx, void *data, int *data_size, |
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AVPacket *avpkt) |
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{ |
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VBLEContext *ctx = avctx->priv_data; |
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AVFrame *pic = avctx->coded_frame; |
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GetBitContext gb; |
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const uint8_t *src = avpkt->data; |
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int version; |
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int offset = 0; |
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int width_uv = avctx->width / 2, height_uv = avctx->height / 2; |
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pic->reference = 0; |
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/* Clear buffer if need be */ |
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if (pic->data[0]) |
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avctx->release_buffer(avctx, pic); |
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/* Allocate buffer */ |
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if (avctx->get_buffer(avctx, pic) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n"); |
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return AVERROR(ENOMEM); |
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} |
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/* Set flags */ |
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pic->key_frame = 1; |
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pic->pict_type = FF_I_TYPE; |
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/* Version should always be 1 */ |
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version = AV_RL32(src); |
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if (version != 1) { |
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av_log(avctx, AV_LOG_ERROR, "Unsupported VBLE Version: %d\n", version); |
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return AVERROR_INVALIDDATA; |
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} |
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init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8); |
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/* Unpack */ |
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if (vble_unpack(ctx, &gb) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "Invalid Code\n"); |
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return AVERROR_INVALIDDATA; |
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} |
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/* Restore planes. Should be almost identical to Huffyuv's. */ |
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vble_restore_plane(ctx, 0, offset, avctx->width, avctx->height); |
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/* Chroma */ |
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if (!(ctx->flags & CODEC_FLAG_GRAY)) { |
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offset += avctx->width * avctx->height; |
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vble_restore_plane(ctx, 1, offset, width_uv, height_uv); |
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offset += width_uv * height_uv; |
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vble_restore_plane(ctx, 2, offset, width_uv, height_uv); |
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} |
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*data_size = sizeof(AVFrame); |
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*(AVFrame *)data = *pic; |
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return avpkt->size; |
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} |
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static av_cold int vble_decode_close(AVCodecContext *avctx) |
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{ |
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VBLEContext *ctx = avctx->priv_data; |
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AVFrame *pic = avctx->coded_frame; |
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if (pic->data[0]) |
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avctx->release_buffer(avctx, pic); |
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av_freep(&avctx->coded_frame); |
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av_freep(&ctx->len); |
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av_freep(&ctx->val); |
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return 0; |
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} |
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static av_always_inline int vble_error_close(AVCodecContext *avctx, |
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const char *message) |
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{ |
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av_log(avctx, AV_LOG_ERROR, message); |
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vble_decode_close(avctx); |
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return AVERROR(ENOMEM); |
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} |
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static av_cold int vble_decode_init(AVCodecContext *avctx) |
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{ |
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VBLEContext *ctx = avctx->priv_data; |
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/* Stash for later use */ |
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ctx->avctx = avctx; |
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ctx->flags = avctx->flags; |
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avctx->pix_fmt = PIX_FMT_YUV420P; |
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avctx->bits_per_raw_sample = 8; |
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avctx->coded_frame = avcodec_alloc_frame(); |
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if (!avctx->coded_frame) |
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return vble_error_close(avctx, "Could not allocate frame.\n"); |
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ctx->size = avpicture_get_size(avctx->pix_fmt, |
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avctx->width, avctx->height); |
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ctx->len = av_malloc(ctx->size * sizeof(*ctx->len)); |
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if (!ctx->len) |
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return vble_error_close(avctx, "Could not allocate lengths buffer.\n"); |
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ctx->val = av_malloc(ctx->size * sizeof(*ctx->val)); |
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if (!ctx->val) |
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return vble_error_close(avctx, "Could not allocate values buffer.\n"); |
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return 0; |
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} |
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AVCodec ff_vble_decoder = { |
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.name = "vble", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.id = CODEC_ID_VBLE, |
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.priv_data_size = sizeof(VBLEContext), |
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.init = vble_decode_init, |
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.close = vble_decode_close, |
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.decode = vble_decode_frame, |
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.capabilities = CODEC_CAP_DR1, |
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.long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"), |
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}; |
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