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-rw-r--r--libavcodec/xfaceenc.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/libavcodec/xfaceenc.c b/libavcodec/xfaceenc.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 encoder, based on libcompface, by James Ashton.
+ */
+
+#include "xface.h"
+#include "avcodec.h"
+#include "internal.h"
+#include "libavutil/avassert.h"
+
+typedef struct XFaceContext {
+ AVClass *class;
+ uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
+ int max_line_len; ///< max line length for compressed data
+ int set_header; ///< set X-Face header in the output
+} XFaceContext;
+
+static int all_same(char *bitmap, int w, int h)
+{
+ char val, *row;
+ int x;
+
+ val = *bitmap;
+ while (h--) {
+ row = bitmap;
+ x = w;
+ while (x--)
+ if (*(row++) != val)
+ return 0;
+ bitmap += XFACE_WIDTH;
+ }
+ return 1;
+}
+
+static int all_black(char *bitmap, int w, int h)
+{
+ if (w > 3) {
+ w /= 2;
+ h /= 2;
+ return (all_black(bitmap, w, h) && all_black(bitmap + w, w, h) &&
+ all_black(bitmap + XFACE_WIDTH * h, w, h) &&
+ all_black(bitmap + XFACE_WIDTH * h + w, w, h));
+ } else {
+ /* at least one pixel in the 2x2 grid is non-zero */
+ return *bitmap || *(bitmap + 1) ||
+ *(bitmap + XFACE_WIDTH) || *(bitmap + XFACE_WIDTH + 1);
+ }
+}
+
+static int all_white(char *bitmap, int w, int h)
+{
+ return *bitmap == 0 && all_same(bitmap, w, h);
+}
+
+typedef struct {
+ ProbRange prob_ranges[XFACE_PIXELS*2];
+ int prob_ranges_idx;
+} ProbRangesQueue;
+
+static inline int pq_push(ProbRangesQueue *pq, const ProbRange *p)
+{
+ if (pq->prob_ranges_idx >= XFACE_PIXELS * 2 - 1)
+ return -1;
+ pq->prob_ranges[pq->prob_ranges_idx++] = *p;
+ return 0;
+}
+
+static void push_greys(ProbRangesQueue *pq, char *bitmap, int w, int h)
+{
+ if (w > 3) {
+ w /= 2;
+ h /= 2;
+ push_greys(pq, bitmap, w, h);
+ push_greys(pq, bitmap + w, w, h);
+ push_greys(pq, bitmap + XFACE_WIDTH * h, w, h);
+ push_greys(pq, bitmap + XFACE_WIDTH * h + w, w, h);
+ } else {
+ const ProbRange *p = ff_xface_probranges_2x2 +
+ *bitmap +
+ 2 * *(bitmap + 1) +
+ 4 * *(bitmap + XFACE_WIDTH) +
+ 8 * *(bitmap + XFACE_WIDTH + 1);
+ pq_push(pq, p);
+ }
+}
+
+static void encode_block(char *bitmap, int w, int h, int level, ProbRangesQueue *pq)
+{
+ if (all_white(bitmap, w, h)) {
+ pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_WHITE]);
+ } else if (all_black(bitmap, w, h)) {
+ pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_BLACK]);
+ push_greys(pq, bitmap, w, h);
+ } else {
+ pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_GREY]);
+ w /= 2;
+ h /= 2;
+ level++;
+ encode_block(bitmap, w, h, level, pq);
+ encode_block(bitmap + w, w, h, level, pq);
+ encode_block(bitmap + h * XFACE_WIDTH, w, h, level, pq);
+ encode_block(bitmap + w + h * XFACE_WIDTH, w, h, level, pq);
+ }
+}
+
+static void push_integer(BigInt *b, const ProbRange *prange)
+{
+ uint8_t r;
+
+ ff_big_div(b, prange->range, &r);
+ ff_big_mul(b, 0);
+ ff_big_add(b, r + prange->offset);
+}
+
+static int xface_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
+ const AVFrame *frame, int *got_packet)
+{
+ XFaceContext *xface = avctx->priv_data;
+ ProbRangesQueue pq = {{{ 0 }}, 0};
+ uint8_t bitmap_copy[XFACE_PIXELS];
+ BigInt b = {0};
+ int i, j, k, ret = 0;
+ const uint8_t *buf;
+ uint8_t *p;
+ char intbuf[XFACE_MAX_DIGITS];
+
+ 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;
+
+ /* convert image from MONOWHITE to 1=black 0=white bitmap */
+ buf = frame->data[0];
+ i = j = 0;
+ do {
+ for (k = 0; k < 8; k++)
+ xface->bitmap[i++] = (buf[j]>>(7-k))&1;
+ if (++j == XFACE_WIDTH/8) {
+ buf += frame->linesize[0];
+ j = 0;
+ }
+ } while (i < XFACE_PIXELS);
+
+ /* create a copy of bitmap */
+ memcpy(bitmap_copy, xface->bitmap, XFACE_PIXELS);
+ ff_xface_generate_face(xface->bitmap, bitmap_copy);
+
+ encode_block(xface->bitmap, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + 16, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + 32, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + XFACE_WIDTH * 16, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + XFACE_WIDTH * 16 + 16, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + XFACE_WIDTH * 16 + 32, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + XFACE_WIDTH * 32, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + XFACE_WIDTH * 32 + 16, 16, 16, 0, &pq);
+ encode_block(xface->bitmap + XFACE_WIDTH * 32 + 32, 16, 16, 0, &pq);
+
+ while (pq.prob_ranges_idx > 0)
+ push_integer(&b, &pq.prob_ranges[--pq.prob_ranges_idx]);
+
+ /* write the inverted big integer in b to intbuf */
+ i = 0;
+ av_assert0(b.nb_words < XFACE_MAX_WORDS);
+ while (b.nb_words) {
+ uint8_t r;
+ ff_big_div(&b, XFACE_PRINTS, &r);
+ av_assert0(i < sizeof(intbuf));
+ intbuf[i++] = r + XFACE_FIRST_PRINT;
+ }
+
+ if ((ret = ff_alloc_packet2(avctx, pkt, i+2, 0)) < 0)
+ return ret;
+
+ /* revert the number, and close the buffer */
+ p = pkt->data;
+ while (--i >= 0)
+ *(p++) = intbuf[i];
+ *(p++) = '\n';
+ *(p++) = 0;
+
+ pkt->flags |= AV_PKT_FLAG_KEY;
+ *got_packet = 1;
+
+ return 0;
+}
+
+AVCodec ff_xface_encoder = {
+ .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),
+ .encode2 = xface_encode_frame,
+ .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
+ .capabilities = AV_CODEC_CAP_INTRA_ONLY,
+};
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