/* * 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 Libav. * * Libav 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. * * Libav 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 Libav; 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 <stdio.h> #include <stdlib.h> #include <string.h> #include "avcodec.h" #include "internal.h" #include "libavutil/internal.h" typedef struct CyuvDecodeContext { AVCodecContext *avctx; int width, height; } CyuvDecodeContext; static av_cold int cyuv_decode_init(AVCodecContext *avctx) { CyuvDecodeContext *s = avctx->priv_data; s->avctx = avctx; s->width = avctx->width; /* width needs to be divisible by 4 for this codec to work */ if (s->width & 0x3) return AVERROR_INVALIDDATA; s->height = avctx->height; avctx->pix_fmt = AV_PIX_FMT_YUV411P; return 0; } static int cyuv_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; CyuvDecodeContext *s=avctx->priv_data; AVFrame *frame = data; 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 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 + s->height * (s->width * 3 / 4)) { av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n", buf_size, 48 + s->height * (s->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) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } y_plane = frame->data[0]; u_plane = frame->data[1]; v_plane = frame->data[2]; /* iterate through each line in the height */ for (y_ptr = 0, u_ptr = 0, v_ptr = 0; y_ptr < (s->height * frame->linesize[0]); y_ptr += frame->linesize[0] - s->width, u_ptr += frame->linesize[1] - s->width / 4, v_ptr += frame->linesize[2] - s->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 = s->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_DECODER AVCodec ff_aura_decoder = { .name = "aura", .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_AURA, .priv_data_size = sizeof(CyuvDecodeContext), .init = cyuv_decode_init, .decode = cyuv_decode_frame, .capabilities = CODEC_CAP_DR1, }; #endif #if CONFIG_CYUV_DECODER AVCodec ff_cyuv_decoder = { .name = "cyuv", .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_CYUV, .priv_data_size = sizeof(CyuvDecodeContext), .init = cyuv_decode_init, .decode = cyuv_decode_frame, .capabilities = CODEC_CAP_DR1, }; #endif