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-rw-r--r--kopete/protocols/msn/webcam/libmimic/encode.c419
1 files changed, 419 insertions, 0 deletions
diff --git a/kopete/protocols/msn/webcam/libmimic/encode.c b/kopete/protocols/msn/webcam/libmimic/encode.c
new file mode 100644
index 00000000..6c8a9de8
--- /dev/null
+++ b/kopete/protocols/msn/webcam/libmimic/encode.c
@@ -0,0 +1,419 @@
+/* Copyright (C) 2005 Ole André Vadla Ravnås <oleavr@gmail.com>
+ *
+ * This library 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.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "mimic-private.h"
+
+#define LUMINANCE_THRESHOLD 32.0f
+#define CHROMINANCE_THRESHOLD 36.0f
+
+static void encode_main(MimCtx *ctx, guchar *out_buf, gboolean is_pframe);
+
+/**
+ * Encode a MIMIC-encoded frame from RGB data.
+ *
+ * @param ctx the mimic context
+ * @param input_buffer buffer containing pixeldata in RGB 24-bpp packed pixel top-down format
+ * @param output_buffer buffer that will receive the MIMIC-encoded frame
+ * (use #mimic_get_property to determine the required buffer size)
+ * @param output_length pointer to an integer that receives the length of the encoded data
+ * written to output_buffer
+ * @param make_keyframe whether the encoder should make this frame a keyframe
+ * @returns #TRUE on success
+ */
+gboolean mimic_encode_frame(MimCtx *ctx,
+ const guchar *input_buffer,
+ guchar *output_buffer,
+ gint *output_length,
+ gboolean make_keyframe)
+{
+ guchar *output_y, *output_cb, *output_cr;
+
+ /*
+ * Some sanity checks.
+ */
+ if (ctx == NULL || input_buffer == NULL ||
+ output_buffer == NULL || output_length == NULL)
+ {
+ return FALSE;
+ }
+
+ if (!ctx->encoder_initialized)
+ return FALSE;
+
+ /*
+ * Initialize state.
+ */
+ ctx->chunk_ptr = (guint32 *) (output_buffer + 20);
+ ctx->cur_chunk = 0;
+ ctx->cur_chunk_len = 0;
+
+ if (ctx->frame_num == 0)
+ make_keyframe = TRUE;
+
+ /*
+ * Write header.
+ */
+ memset(output_buffer, 0, 20);
+ *((guint16 *) (output_buffer + 0)) = GUINT16_TO_LE(256);
+ *((guint16 *) (output_buffer + 2)) = GUINT16_TO_LE(ctx->quality);
+ *((guint16 *) (output_buffer + 4)) = GUINT16_TO_LE(ctx->frame_width);
+ *((guint16 *) (output_buffer + 6)) = GUINT16_TO_LE(ctx->frame_height);
+ *((guint32 *) (output_buffer + 12)) = GUINT32_TO_LE((make_keyframe == 0));
+ *(output_buffer + 16) = ctx->num_coeffs;
+ *(output_buffer + 17) = 0;
+
+ /*
+ * Perform RGB to YUV 420 conversion.
+ */
+ output_y = ctx->cur_frame_buf;
+ output_cr = ctx->cur_frame_buf + ctx->y_size;
+ output_cb = ctx->cur_frame_buf + ctx->y_size + ctx->crcb_size;
+
+ _rgb_to_yuv(input_buffer,
+ output_y,
+ output_cb,
+ output_cr,
+ ctx->frame_width,
+ ctx->frame_height);
+
+ /*
+ * Encode frame.
+ */
+ encode_main(ctx, output_buffer, (make_keyframe == FALSE));
+
+ /*
+ * Write out any pending bits to stream by zero-padding with 32 bits.
+ */
+ _write_bits(ctx, 0, 32);
+
+ /*
+ * Calculate bytes written.
+ */
+ *output_length = (guchar *) ctx->chunk_ptr - output_buffer;
+
+ /*
+ * Increment frame counter.
+ */
+ ctx->frame_num++;
+
+ return TRUE;
+}
+
+static gdouble compare_blocks(const guchar *p1,
+ const guchar *p2,
+ gint stride,
+ gint row_count,
+ gboolean is_chrom);
+
+/*
+ * encode_main
+ *
+ * Main encoding loop.
+ */
+static void encode_main(MimCtx *ctx, guchar *out_buf, gboolean is_pframe)
+{
+ gint x, y, i, offset, chrom_ch;
+ gint dct_block[64];
+ guchar *src, *dst, *p1, *p2;
+ gdouble match;
+ gboolean encoded;
+
+ /*
+ * Round down small differences in luminance channel.
+ */
+ if (is_pframe) {
+
+ p1 = ctx->cur_frame_buf;
+ p2 = ctx->prev_frame_buf;
+
+ for (i = 0; i < ctx->y_size; i++) {
+
+ if (abs(p2[0] - p1[0]) < 7)
+ p1[0] = p2[0];
+
+ p1++;
+ p2++;
+ }
+ }
+
+ /*
+ * Encode Y plane.
+ */
+ for (y = 0; y < ctx->num_vblocks_y; y++) {
+
+ for (x = 0; x < ctx->num_hblocks_y; x++) {
+
+ /* Calculate final offset into buffer. */
+ offset = (ctx->y_stride * 8 * y) + (x * 8);
+
+ src = NULL;
+ encoded = FALSE;
+
+ if (is_pframe) {
+
+ /* Is the current block similar enough to what it was in the previous frame? */
+
+ match = compare_blocks(ctx->cur_frame_buf + offset,
+ ctx->prev_frame_buf + offset,
+ ctx->y_stride, 8,
+ FALSE);
+
+ if (match > LUMINANCE_THRESHOLD) {
+
+ /* Yes: write out '1' to indicate a no-change condition. */
+
+ _write_bits(ctx, 1, 1);
+
+ src = ctx->prev_frame_buf + offset;
+ encoded = TRUE;
+
+ } else {
+
+ /* No: Is the current block similar enough to what it was in one
+ * of the (up to) 15 last frames preceding the previous? */
+
+ gint best_index = 0;
+ gdouble best_match = 0.0;
+
+ gint num_backrefs = ctx->frame_num - 1;
+ if (num_backrefs > 15)
+ num_backrefs = 15;
+
+ for (i = 1; i <= num_backrefs; i++) {
+
+ match = compare_blocks(ctx->buf_ptrs[(ctx->ptr_index + i) % 16] + offset,
+ ctx->cur_frame_buf + offset,
+ ctx->y_stride, 8,
+ FALSE);
+
+ if (match > LUMINANCE_THRESHOLD && match > best_match) {
+ best_index = i;
+ best_match = match;
+ }
+
+ }
+
+ if (best_index != 0) {
+
+ /* Yes: write out '01' to indicate a "change but like previous"-condition,
+ * followed by 4 bits containing the back-reference. */
+ _write_bits(ctx, 0, 1);
+ _write_bits(ctx, 1, 1);
+ _write_bits(ctx, best_index, 4);
+
+ src = ctx->buf_ptrs[(ctx->ptr_index + best_index) % 16] + offset;
+ encoded = TRUE;
+
+ }
+ }
+ }
+
+ if (!encoded) {
+
+ /* Keyframe or in any case no? ;-) Well, encode it then. */
+
+ if (is_pframe) {
+ _write_bits(ctx, 0, 1);
+ _write_bits(ctx, 0, 1);
+ }
+
+ _fdct_quant_block(ctx,
+ dct_block,
+ ctx->cur_frame_buf + offset,
+ ctx->y_stride,
+ FALSE,
+ ctx->num_coeffs);
+
+ _vlc_encode_block(ctx,
+ dct_block,
+ ctx->num_coeffs);
+
+ }
+
+ /* And if there was some kind of no-change condition,
+ * we want to copy the previous block. */
+ if (src != NULL) {
+
+ dst = ctx->cur_frame_buf + offset;
+ for (i = 0; i < 8; i++) {
+
+ memcpy(dst, src, 8);
+
+ src += ctx->y_stride;
+ dst += ctx->y_stride;
+ }
+
+ }
+
+ }
+
+ }
+
+ /*
+ * Encode Cr and Cb planes.
+ */
+ for (chrom_ch = 0; chrom_ch < 2; chrom_ch++) {
+
+ /* Calculate base offset into buffer. */
+ gint base_offset = ctx->y_size + (ctx->crcb_size * chrom_ch);
+
+ for (y = 0; y < ctx->num_vblocks_cbcr; y++) {
+ guchar tmp_block[64];
+ guint num_rows = 8;
+
+ /* The last row of blocks in chrominance for 160x120 resolution
+ * is half the normal height and must be accounted for. */
+ if (y + 1 == ctx->num_vblocks_cbcr && ctx->frame_height % 16 != 0)
+ num_rows = 4;
+
+ for (x = 0; x < ctx->num_hblocks_cbcr; x++) {
+
+ /* Calculate final offset into buffer. */
+ offset = base_offset + (ctx->crcb_stride * 8 * y) + (x * 8);
+
+ src = NULL;
+ encoded = FALSE;
+
+ if (is_pframe) {
+
+ /* Is the current block similar enough to what it was in the previous frame? */
+
+ match = compare_blocks(ctx->prev_frame_buf + offset,
+ ctx->cur_frame_buf + offset,
+ ctx->crcb_stride, num_rows,
+ TRUE);
+
+ if (match > CHROMINANCE_THRESHOLD) {
+
+ /* Yes: write out '0' to indicate a no-change condition. */
+
+ _write_bits(ctx, 0, 1);
+
+ encoded = TRUE;
+
+ src = ctx->prev_frame_buf + offset;
+ dst = ctx->cur_frame_buf + offset;
+ for (i = 0; i < num_rows; i++) {
+
+ memcpy(dst, src, 8);
+
+ src += ctx->crcb_stride;
+ dst += ctx->crcb_stride;
+ }
+ }
+
+ }
+
+ if (!encoded) {
+
+ /* Keyframe or just not similar enough? ;-) Well, encode it then. */
+
+ if (is_pframe)
+ _write_bits(ctx, 1, 1);
+
+ /* Use a temporary array to handle cases where the
+ * current block is not of normal height (see above). */
+ src = ctx->cur_frame_buf + offset;
+ dst = tmp_block;
+ for (i = 0; i < 8; i++) {
+
+ memcpy(dst, src, 8);
+
+ if (i < (num_rows - 1))
+ src += ctx->crcb_stride;
+ dst += 8;
+ }
+
+ _fdct_quant_block(ctx,
+ dct_block,
+ tmp_block,
+ 8,
+ TRUE,
+ ctx->num_coeffs);
+
+ _vlc_encode_block(ctx,
+ dct_block,
+ ctx->num_coeffs);
+
+ }
+
+ }
+
+ }
+
+ }
+
+ /*
+ * Make a copy of the current frame and store in
+ * the circular pointer list of 16 entries.
+ */
+ ctx->prev_frame_buf = ctx->buf_ptrs[ctx->ptr_index];
+ memcpy(ctx->prev_frame_buf, ctx->cur_frame_buf,
+ ctx->y_size + (ctx->crcb_size * 2));
+
+ if (--ctx->ptr_index < 0)
+ ctx->ptr_index = 15;
+}
+
+/*
+ * compare_blocks
+ *
+ * Helper-function used to compare two blocks and
+ * determine how similar they are.
+ */
+static gdouble compare_blocks(const guchar *p1,
+ const guchar *p2,
+ gint stride,
+ gint row_count,
+ gboolean is_chrom)
+{
+ gint i, j, sum;
+ gdouble d;
+
+ sum = 0;
+
+ for (i = 0; i < row_count; i++) {
+
+ for (j = 0; j < 8; j++) {
+
+ gint d = p2[j] - p1[j];
+
+ sum += d * d;
+ }
+
+ p1 += stride;
+ p2 += stride;
+ }
+
+ if (is_chrom) {
+ if (row_count == 8)
+ d = sum * 0.015625;
+ else
+ d = sum * 0.03125;
+ } else {
+ d = sum / 64;
+ }
+
+ if (d == 0.0f)
+ return 100.0f;
+ else
+ return (10.0f * log(65025.0f / d)) / G_LN10;
+}
+
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