/* * Creative YUV (CYUV) Video Decoder *   by Mike Melanson (melanson@pcisys.net) * based on "Creative YUV (CYUV) stream format for AVI": *   http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt * * Copyright (C) 2003 The FFmpeg project * * 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 * Creative YUV (CYUV) Video Decoder. */ #include "config_components.h" #include <string.h> #include "avcodec.h"#include "codec_internal.h"#include "decode.h"#include "libavutil/internal.h" static av_cold int cyuv_decode_init(AVCodecContext *avctx){    /* width needs to be divisible by 4 for this codec to work */    if (avctx->width & 0x3)        return AVERROR_INVALIDDATA;     return 0;} static int cyuv_decode_frame(AVCodecContext *avctx, AVFrame *frame,                             int *got_frame, AVPacket *avpkt){    const uint8_t *buf = avpkt->data;    int buf_size = avpkt->size;     unsigned char *y_plane;    unsigned char *u_plane;    unsigned char *v_plane;    int y_ptr;    int u_ptr;    int v_ptr;     /* prediction error tables (make it clear that they are signed values) */    const signed char *y_table = (const signed char*)buf +  0;    const signed char *u_table = (const signed char*)buf + 16;    const signed char *v_table = (const signed char*)buf + 32;     unsigned char y_pred, u_pred, v_pred;    int stream_ptr;    unsigned char cur_byte;    int pixel_groups;    int rawsize = avctx->height * FFALIGN(avctx->width,2) * 2;    int ret;     if (avctx->codec_id == AV_CODEC_ID_AURA) {        y_table = u_table;        u_table = v_table;    }    /* sanity check the buffer size: A buffer has 3x16-bytes tables     * followed by (height) lines each with 3 bytes to represent groups     * of 4 pixels. Thus, the total size of the buffer ought to be:     *    (3 * 16) + height * (width * 3 / 4) */    if (buf_size == 48 + avctx->height * (avctx->width * 3 / 4)) {        avctx->pix_fmt = AV_PIX_FMT_YUV411P;    } else if(buf_size == rawsize ) {        avctx->pix_fmt = AV_PIX_FMT_UYVY422;    } else {        av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",               buf_size, 48 + avctx->height * (avctx->width * 3 / 4));        return AVERROR_INVALIDDATA;    }     /* pixel data starts 48 bytes in, after 3x16-byte tables */    stream_ptr = 48;     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)        return ret;     y_plane = frame->data[0];    u_plane = frame->data[1];    v_plane = frame->data[2];     if (buf_size == rawsize) {        int linesize = FFALIGN(avctx->width, 2) * 2;        y_plane += frame->linesize[0] * avctx->height;        for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) {            y_plane -= frame->linesize[0];            memcpy(y_plane, buf+stream_ptr, linesize);        }    } else {     /* iterate through each line in the height */    for (y_ptr = 0, u_ptr = 0, v_ptr = 0;         y_ptr < (avctx->height * frame->linesize[0]);         y_ptr += frame->linesize[0] - avctx->width,         u_ptr += frame->linesize[1] - avctx->width / 4,         v_ptr += frame->linesize[2] - avctx->width / 4) {         /* reset predictors */        cur_byte = buf[stream_ptr++];        u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;        y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;         cur_byte = buf[stream_ptr++];        v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;        y_pred += y_table[cur_byte & 0x0F];        y_plane[y_ptr++] = y_pred;         cur_byte = buf[stream_ptr++];        y_pred += y_table[cur_byte & 0x0F];        y_plane[y_ptr++] = y_pred;        y_pred += y_table[(cur_byte & 0xF0) >> 4];        y_plane[y_ptr++] = y_pred;         /* iterate through the remaining pixel groups (4 pixels/group) */        pixel_groups = avctx->width / 4 - 1;        while (pixel_groups--) {             cur_byte = buf[stream_ptr++];            u_pred += u_table[(cur_byte & 0xF0) >> 4];            u_plane[u_ptr++] = u_pred;            y_pred += y_table[cur_byte & 0x0F];            y_plane[y_ptr++] = y_pred;             cur_byte = buf[stream_ptr++];            v_pred += v_table[(cur_byte & 0xF0) >> 4];            v_plane[v_ptr++] = v_pred;            y_pred += y_table[cur_byte & 0x0F];            y_plane[y_ptr++] = y_pred;             cur_byte = buf[stream_ptr++];            y_pred += y_table[cur_byte & 0x0F];            y_plane[y_ptr++] = y_pred;            y_pred += y_table[(cur_byte & 0xF0) >> 4];            y_plane[y_ptr++] = y_pred;         }    }    }     *got_frame = 1;     return buf_size;} #if CONFIG_AURA_DECODERconst FFCodec ff_aura_decoder = {    .p.name         = "aura",    CODEC_LONG_NAME("Auravision AURA"),    .p.type         = AVMEDIA_TYPE_VIDEO,    .p.id           = AV_CODEC_ID_AURA,    .init           = cyuv_decode_init,    FF_CODEC_DECODE_CB(cyuv_decode_frame),    .p.capabilities = AV_CODEC_CAP_DR1,};#endif #if CONFIG_CYUV_DECODERconst FFCodec ff_cyuv_decoder = {    .p.name         = "cyuv",    CODEC_LONG_NAME("Creative YUV (CYUV)"),    .p.type         = AVMEDIA_TYPE_VIDEO,    .p.id           = AV_CODEC_ID_CYUV,    .init           = cyuv_decode_init,    FF_CODEC_DECODE_CB(cyuv_decode_frame),    .p.capabilities = AV_CODEC_CAP_DR1,};#endif