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-rw-r--r--libavcodec/xfacedec.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/libavcodec/xfacedec.c b/libavcodec/xfacedec.c
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+/*
+ * Copyright (c) 1990 James Ashton - Sydney University
+ * Copyright (c) 2012 Stefano Sabatini
+ *
+ * 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
+ * X-Face decoder, based on libcompface, by James Ashton.
+ */
+
+#include "libavutil/pixdesc.h"
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+#include "xface.h"
+
+static int pop_integer(BigInt *b, const ProbRange *pranges)
+{
+ uint8_t r;
+ int i;
+
+ /* extract the last byte into r, and shift right b by 8 bits */
+ ff_big_div(b, 0, &r);
+
+ i = 0;
+ while (r < pranges->offset || r >= pranges->range + pranges->offset) {
+ pranges++;
+ i++;
+ }
+ ff_big_mul(b, pranges->range);
+ ff_big_add(b, r - pranges->offset);
+ return i;
+}
+
+static void pop_greys(BigInt *b, char *bitmap, int w, int h)
+{
+ if (w > 3) {
+ w /= 2;
+ h /= 2;
+ pop_greys(b, bitmap, w, h);
+ pop_greys(b, bitmap + w, w, h);
+ pop_greys(b, bitmap + XFACE_WIDTH * h, w, h);
+ pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h);
+ } else {
+ w = pop_integer(b, ff_xface_probranges_2x2);
+ if (w & 1) bitmap[0] = 1;
+ if (w & 2) bitmap[1] = 1;
+ if (w & 4) bitmap[XFACE_WIDTH] = 1;
+ if (w & 8) bitmap[XFACE_WIDTH + 1] = 1;
+ }
+}
+
+static void decode_block(BigInt *b, char *bitmap, int w, int h, int level)
+{
+ switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) {
+ case XFACE_COLOR_WHITE:
+ return;
+ case XFACE_COLOR_BLACK:
+ pop_greys(b, bitmap, w, h);
+ return;
+ default:
+ w /= 2;
+ h /= 2;
+ level++;
+ decode_block(b, bitmap, w, h, level);
+ decode_block(b, bitmap + w, w, h, level);
+ decode_block(b, bitmap + h * XFACE_WIDTH, w, h, level);
+ decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level);
+ return;
+ }
+}
+
+typedef struct XFaceContext {
+ uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
+} XFaceContext;
+
+static av_cold int xface_decode_init(AVCodecContext *avctx)
+{
+ if (avctx->width || avctx->height) {
+ if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Size value %dx%d not supported, only accepts a size of %dx%d\n",
+ avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
+ return AVERROR(EINVAL);
+ }
+ }
+
+ avctx->width = XFACE_WIDTH;
+ avctx->height = XFACE_HEIGHT;
+ avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
+
+ return 0;
+}
+
+static int xface_decode_frame(AVCodecContext *avctx,
+ void *data, int *got_frame,
+ AVPacket *avpkt)
+{
+ XFaceContext *xface = avctx->priv_data;
+ int ret, i, j, k;
+ uint8_t byte;
+ BigInt b = {0};
+ char *buf;
+ int64_t c;
+ AVFrame *frame = data;
+
+ if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+ return ret;
+
+ for (i = 0, k = 0; avpkt->data[i] && i < avpkt->size; i++) {
+ c = avpkt->data[i];
+
+ /* ignore invalid digits */
+ if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT)
+ continue;
+
+ if (++k > XFACE_MAX_DIGITS) {
+ av_log(avctx, AV_LOG_WARNING,
+ "Buffer is longer than expected, truncating at byte %d\n", i);
+ break;
+ }
+ ff_big_mul(&b, XFACE_PRINTS);
+ ff_big_add(&b, c - XFACE_FIRST_PRINT);
+ }
+
+ /* decode image and put it in bitmap */
+ memset(xface->bitmap, 0, XFACE_PIXELS);
+ buf = xface->bitmap;
+ decode_block(&b, buf, 16, 16, 0);
+ decode_block(&b, buf + 16, 16, 16, 0);
+ decode_block(&b, buf + 32, 16, 16, 0);
+ decode_block(&b, buf + XFACE_WIDTH * 16, 16, 16, 0);
+ decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0);
+ decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0);
+ decode_block(&b, buf + XFACE_WIDTH * 32 , 16, 16, 0);
+ decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0);
+ decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0);
+
+ ff_xface_generate_face(xface->bitmap, xface->bitmap);
+
+ /* convert image from 1=black 0=white bitmap to MONOWHITE */
+ buf = frame->data[0];
+ for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) {
+ byte += xface->bitmap[i];
+ if (k == 7) {
+ buf[j++] = byte;
+ byte = k = 0;
+ } else {
+ k++;
+ byte <<= 1;
+ }
+ if (j == XFACE_WIDTH/8) {
+ j = 0;
+ buf += frame->linesize[0];
+ }
+ }
+
+ *got_frame = 1;
+
+ return avpkt->size;
+}
+
+AVCodec ff_xface_decoder = {
+ .name = "xface",
+ .long_name = NULL_IF_CONFIG_SMALL("X-face image"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_XFACE,
+ .priv_data_size = sizeof(XFaceContext),
+ .init = xface_decode_init,
+ .decode = xface_decode_frame,
+ .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
+};
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