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![Vittorio Giovara](/assets/img/avatar_default.png)
Express bitfields more simply. Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
143 lines
4.4 KiB
C
143 lines
4.4 KiB
C
/*
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* ATI VCR1 codec
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* Copyright (c) 2003 Michael Niedermayer
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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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* ATI VCR1 codec
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*/
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#include "avcodec.h"
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#include "internal.h"
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#include "libavutil/internal.h"
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typedef struct VCR1Context {
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int delta[16];
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int offset[4];
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} VCR1Context;
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static av_cold int vcr1_decode_init(AVCodecContext *avctx)
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{
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avctx->pix_fmt = AV_PIX_FMT_YUV410P;
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if (avctx->width & 7) {
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av_log(avctx, AV_LOG_ERROR, "Width %d is not divisble by 8.\n", avctx->width);
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return AVERROR_INVALIDDATA;
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}
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return 0;
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}
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static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
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int *got_frame, AVPacket *avpkt)
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{
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const uint8_t *buf = avpkt->data;
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int buf_size = avpkt->size;
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VCR1Context *const a = avctx->priv_data;
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AVFrame *const p = data;
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const uint8_t *bytestream = buf;
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int i, x, y, ret;
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if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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return ret;
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}
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p->pict_type = AV_PICTURE_TYPE_I;
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p->key_frame = 1;
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if (buf_size < 32)
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goto packet_small;
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for (i = 0; i < 16; i++) {
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a->delta[i] = *bytestream++;
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bytestream++;
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buf_size--;
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}
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for (y = 0; y < avctx->height; y++) {
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int offset;
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uint8_t *luma = &p->data[0][y * p->linesize[0]];
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if ((y & 3) == 0) {
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uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
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uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];
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if (buf_size < 4 + avctx->width)
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goto packet_small;
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for (i = 0; i < 4; i++)
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a->offset[i] = *bytestream++;
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buf_size -= 4;
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offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
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for (x = 0; x < avctx->width; x += 4) {
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luma[0] = offset += a->delta[bytestream[2] & 0xF];
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luma[1] = offset += a->delta[bytestream[2] >> 4];
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luma[2] = offset += a->delta[bytestream[0] & 0xF];
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luma[3] = offset += a->delta[bytestream[0] >> 4];
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luma += 4;
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*cb++ = bytestream[3];
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*cr++ = bytestream[1];
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bytestream += 4;
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buf_size -= 4;
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}
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} else {
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if (buf_size < avctx->width / 2)
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goto packet_small;
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offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
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for (x = 0; x < avctx->width; x += 8) {
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luma[0] = offset += a->delta[bytestream[2] & 0xF];
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luma[1] = offset += a->delta[bytestream[2] >> 4];
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luma[2] = offset += a->delta[bytestream[3] & 0xF];
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luma[3] = offset += a->delta[bytestream[3] >> 4];
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luma[4] = offset += a->delta[bytestream[0] & 0xF];
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luma[5] = offset += a->delta[bytestream[0] >> 4];
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luma[6] = offset += a->delta[bytestream[1] & 0xF];
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luma[7] = offset += a->delta[bytestream[1] >> 4];
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luma += 8;
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bytestream += 4;
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buf_size -= 4;
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}
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}
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}
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*got_frame = 1;
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return buf_size;
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packet_small:
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av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n");
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return AVERROR_INVALIDDATA;
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}
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AVCodec ff_vcr1_decoder = {
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.name = "vcr1",
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.long_name = NULL_IF_CONFIG_SMALL("ATI VCR1"),
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.type = AVMEDIA_TYPE_VIDEO,
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.id = AV_CODEC_ID_VCR1,
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.priv_data_size = sizeof(VCR1Context),
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.init = vcr1_decode_init,
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.decode = vcr1_decode_frame,
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.capabilities = AV_CODEC_CAP_DR1,
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};
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