yading@10: /*
yading@10:  * Copyright (c) 1990 James Ashton - Sydney University
yading@10:  * Copyright (c) 2012 Stefano Sabatini
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * X-Face decoder, based on libcompface, by James Ashton.
yading@10:  */
yading@10: 
yading@10: #include "libavutil/pixdesc.h"
yading@10: #include "avcodec.h"
yading@10: #include "bytestream.h"
yading@10: #include "internal.h"
yading@10: #include "xface.h"
yading@10: 
yading@10: static int pop_integer(BigInt *b, const ProbRange *pranges)
yading@10: {
yading@10:     uint8_t r;
yading@10:     int i;
yading@10: 
yading@10:     /* extract the last byte into r, and shift right b by 8 bits */
yading@10:     ff_big_div(b, 0, &r);
yading@10: 
yading@10:     i = 0;
yading@10:     while (r < pranges->offset || r >= pranges->range + pranges->offset) {
yading@10:         pranges++;
yading@10:         i++;
yading@10:     }
yading@10:     ff_big_mul(b, pranges->range);
yading@10:     ff_big_add(b, r - pranges->offset);
yading@10:     return i;
yading@10: }
yading@10: 
yading@10: static void pop_greys(BigInt *b, char *bitmap, int w, int h)
yading@10: {
yading@10:     if (w > 3) {
yading@10:         w /= 2;
yading@10:         h /= 2;
yading@10:         pop_greys(b, bitmap,                       w, h);
yading@10:         pop_greys(b, bitmap + w,                   w, h);
yading@10:         pop_greys(b, bitmap + XFACE_WIDTH * h,     w, h);
yading@10:         pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h);
yading@10:     } else {
yading@10:         w = pop_integer(b, ff_xface_probranges_2x2);
yading@10:         if (w & 1) bitmap[0]               = 1;
yading@10:         if (w & 2) bitmap[1]               = 1;
yading@10:         if (w & 4) bitmap[XFACE_WIDTH]     = 1;
yading@10:         if (w & 8) bitmap[XFACE_WIDTH + 1] = 1;
yading@10:     }
yading@10: }
yading@10: 
yading@10: static void decode_block(BigInt *b, char *bitmap, int w, int h, int level)
yading@10: {
yading@10:     switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) {
yading@10:     case XFACE_COLOR_WHITE:
yading@10:         return;
yading@10:     case XFACE_COLOR_BLACK:
yading@10:         pop_greys(b, bitmap, w, h);
yading@10:         return;
yading@10:     default:
yading@10:         w /= 2;
yading@10:         h /= 2;
yading@10:         level++;
yading@10:         decode_block(b, bitmap,                       w, h, level);
yading@10:         decode_block(b, bitmap + w,                   w, h, level);
yading@10:         decode_block(b, bitmap + h * XFACE_WIDTH,     w, h, level);
yading@10:         decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level);
yading@10:         return;
yading@10:     }
yading@10: }
yading@10: 
yading@10: typedef struct XFaceContext {
yading@10:     uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
yading@10: } XFaceContext;
yading@10: 
yading@10: static av_cold int xface_decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     if (avctx->width || avctx->height) {
yading@10:         if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
yading@10:             av_log(avctx, AV_LOG_ERROR,
yading@10:                    "Size value %dx%d not supported, only accepts a size of %dx%d\n",
yading@10:                    avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
yading@10:             return AVERROR(EINVAL);
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     avctx->width   = XFACE_WIDTH;
yading@10:     avctx->height  = XFACE_HEIGHT;
yading@10:     avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int xface_decode_frame(AVCodecContext *avctx,
yading@10:                               void *data, int *got_frame,
yading@10:                               AVPacket *avpkt)
yading@10: {
yading@10:     XFaceContext *xface = avctx->priv_data;
yading@10:     int ret, i, j, k;
yading@10:     uint8_t byte;
yading@10:     BigInt b = {0};
yading@10:     char *buf;
yading@10:     int64_t c;
yading@10:     AVFrame *frame = data;
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     for (i = 0, k = 0; avpkt->data[i] && i < avpkt->size; i++) {
yading@10:         c = avpkt->data[i];
yading@10: 
yading@10:         /* ignore invalid digits */
yading@10:         if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT)
yading@10:             continue;
yading@10: 
yading@10:         if (++k > XFACE_MAX_DIGITS) {
yading@10:             av_log(avctx, AV_LOG_WARNING,
yading@10:                    "Buffer is longer than expected, truncating at byte %d\n", i);
yading@10:             break;
yading@10:         }
yading@10:         ff_big_mul(&b, XFACE_PRINTS);
yading@10:         ff_big_add(&b, c - XFACE_FIRST_PRINT);
yading@10:     }
yading@10: 
yading@10:     /* decode image and put it in bitmap */
yading@10:     memset(xface->bitmap, 0, XFACE_PIXELS);
yading@10:     buf = xface->bitmap;
yading@10:     decode_block(&b, buf,                         16, 16, 0);
yading@10:     decode_block(&b, buf + 16,                    16, 16, 0);
yading@10:     decode_block(&b, buf + 32,                    16, 16, 0);
yading@10:     decode_block(&b, buf + XFACE_WIDTH * 16,      16, 16, 0);
yading@10:     decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0);
yading@10:     decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0);
yading@10:     decode_block(&b, buf + XFACE_WIDTH * 32     , 16, 16, 0);
yading@10:     decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0);
yading@10:     decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0);
yading@10: 
yading@10:     ff_xface_generate_face(xface->bitmap, xface->bitmap);
yading@10: 
yading@10:     /* convert image from 1=black 0=white bitmap to MONOWHITE */
yading@10:     buf = frame->data[0];
yading@10:     for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) {
yading@10:         byte += xface->bitmap[i];
yading@10:         if (k == 7) {
yading@10:             buf[j++] = byte;
yading@10:             byte = k = 0;
yading@10:         } else {
yading@10:             k++;
yading@10:             byte <<= 1;
yading@10:         }
yading@10:         if (j == XFACE_WIDTH/8) {
yading@10:             j = 0;
yading@10:             buf += frame->linesize[0];
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     *got_frame = 1;
yading@10: 
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: AVCodec ff_xface_decoder = {
yading@10:     .name           = "xface",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_XFACE,
yading@10:     .priv_data_size = sizeof(XFaceContext),
yading@10:     .init           = xface_decode_init,
yading@10:     .decode         = xface_decode_frame,
yading@10:     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("X-face image"),
yading@10: };