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-rw-r--r--libavcodec/escape130.c319
1 files changed, 319 insertions, 0 deletions
diff --git a/libavcodec/escape130.c b/libavcodec/escape130.c
new file mode 100644
index 0000000000..47e7f11d6c
--- /dev/null
+++ b/libavcodec/escape130.c
@@ -0,0 +1,319 @@
+/*
+ * Escape 130 Video Decoder
+ * Copyright (C) 2008 Eli Friedman (eli.friedman <at> gmail.com)
+ *
+ * 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
+ */
+
+#include "avcodec.h"
+
+#define BITSTREAM_READER_LE
+#include "get_bits.h"
+
+typedef struct Escape130Context {
+ AVFrame frame;
+ uint8_t *bases;
+} Escape130Context;
+
+/**
+ * Initialize the decoder
+ * @param avctx decoder context
+ * @return 0 success, negative on error
+ */
+static av_cold int escape130_decode_init(AVCodecContext *avctx)
+{
+ Escape130Context *s = avctx->priv_data;
+ avctx->pix_fmt = PIX_FMT_YUV420P;
+
+ if((avctx->width&1) || (avctx->height&1)){
+ av_log(avctx, AV_LOG_ERROR, "Dimensions are not a multiple of the block size\n");
+ return AVERROR(EINVAL);
+ }
+
+ s->bases= av_malloc(avctx->width * avctx->height /4);
+
+ return 0;
+}
+
+static av_cold int escape130_decode_close(AVCodecContext *avctx)
+{
+ Escape130Context *s = avctx->priv_data;
+
+ if (s->frame.data[0])
+ avctx->release_buffer(avctx, &s->frame);
+
+ av_freep(&s->bases);
+
+ return 0;
+}
+
+static unsigned decode_skip_count(GetBitContext* gb) {
+ unsigned value;
+ // This function reads a maximum of 27 bits,
+ // which is within the padding space
+ if (get_bits_left(gb) < 1+3)
+ return -1;
+
+ value = get_bits1(gb);
+ if (value)
+ return 0;
+
+ value = get_bits(gb, 3);
+ if (value)
+ return value;
+
+ value = get_bits(gb, 8);
+ if (value)
+ return value + 7;
+
+ value = get_bits(gb, 15);
+ if (value)
+ return value + 262;
+
+ return -1;
+}
+
+/**
+ * Decode a single frame
+ * @param avctx decoder context
+ * @param data decoded frame
+ * @param data_size size of the decoded frame
+ * @param buf input buffer
+ * @param buf_size input buffer size
+ * @return 0 success, -1 on error
+ */
+static int escape130_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ AVPacket *avpkt)
+{
+ const uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
+ Escape130Context *s = avctx->priv_data;
+
+ GetBitContext gb;
+ unsigned i;
+
+ uint8_t *old_y, *old_cb, *old_cr,
+ *new_y, *new_cb, *new_cr;
+ unsigned old_y_stride, old_cb_stride, old_cr_stride,
+ new_y_stride, new_cb_stride, new_cr_stride;
+ unsigned total_blocks = avctx->width * avctx->height / 4,
+ block_index, row_index = 0;
+ unsigned y[4] = {0}, cb = 16, cr = 16;
+ unsigned skip = -1;
+ unsigned y_base = 0;
+ uint8_t *yb= s->bases;
+
+ AVFrame new_frame = { { 0 } };
+
+ init_get_bits(&gb, buf, buf_size * 8);
+
+ if (get_bits_left(&gb) < 128)
+ return -1;
+
+ // Header; no useful information in here
+ skip_bits_long(&gb, 128);
+
+ new_frame.reference = 3;
+ if (avctx->get_buffer(avctx, &new_frame)) {
+ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+ return -1;
+ }
+
+ new_y = new_frame.data[0];
+ new_cb = new_frame.data[1];
+ new_cr = new_frame.data[2];
+ new_y_stride = new_frame.linesize[0];
+ new_cb_stride = new_frame.linesize[1];
+ new_cr_stride = new_frame.linesize[2];
+ old_y = s->frame.data[0];
+ old_cb = s->frame.data[1];
+ old_cr = s->frame.data[2];
+ old_y_stride = s->frame.linesize[0];
+ old_cb_stride = s->frame.linesize[1];
+ old_cr_stride = s->frame.linesize[2];
+
+ av_log(avctx, AV_LOG_DEBUG,
+ "Strides: %i, %i\n",
+ new_y_stride, new_cb_stride);
+
+ for (block_index = 0; block_index < total_blocks; block_index++) {
+ // Note that this call will make us skip the rest of the blocks
+ // if the frame prematurely ends
+ if (skip == -1)
+ skip = decode_skip_count(&gb);
+
+ if (skip) {
+ if (old_y) {
+ y[0] = old_y[0] / 4;
+ y[1] = old_y[1] / 4;
+ y[2] = old_y[old_y_stride] / 4;
+ y[3] = old_y[old_y_stride+1] / 4;
+ y_base= yb[0];
+ cb = old_cb[0] / 8;
+ cr = old_cr[0] / 8;
+ } else {
+ y_base=y[0] = y[1] = y[2] = y[3] = 0;
+ cb = cr = 16;
+ }
+ } else {
+ if (get_bits1(&gb)) {
+ static const uint8_t offset_table[] = {2, 4, 10, 20};
+ static const int8_t sign_table[64][4] =
+ { {0, 0, 0, 0},
+ {-1, 1, 0, 0},
+ {1, -1, 0, 0},
+ {-1, 0, 1, 0},
+ {-1, 1, 1, 0},
+ {0, -1, 1, 0},
+ {1, -1, 1, 0},
+ {-1, -1, 1, 0},
+ {1, 0, -1, 0},
+ {0, 1, -1, 0},
+ {1, 1, -1, 0},
+ {-1, 1, -1, 0},
+ {1, -1, -1, 0},
+ {-1, 0, 0, 1},
+ {-1, 1, 0, 1},
+ {0, -1, 0, 1},
+
+ {0, 0, 0, 0},
+ {1, -1, 0, 1},
+ {-1, -1, 0, 1},
+ {-1, 0, 1, 1},
+ {-1, 1, 1, 1},
+ {0, -1, 1, 1},
+ {1, -1, 1, 1},
+ {-1, -1, 1, 1},
+ {0, 0, -1, 1},
+ {1, 0, -1, 1},
+ {-1, 0, -1, 1},
+ {0, 1, -1, 1},
+ {1, 1, -1, 1},
+ {-1, 1, -1, 1},
+ {0, -1, -1, 1},
+ {1, -1, -1, 1},
+
+ {0, 0, 0, 0},
+ {-1, -1, -1, 1},
+ {1, 0, 0, -1},
+ {0, 1, 0, -1},
+ {1, 1, 0, -1},
+ {-1, 1, 0, -1},
+ {1, -1, 0, -1},
+ {0, 0, 1, -1},
+ {1, 0, 1, -1},
+ {-1, 0, 1, -1},
+ {0, 1, 1, -1},
+ {1, 1, 1, -1},
+ {-1, 1, 1, -1},
+ {0, -1, 1, -1},
+ {1, -1, 1, -1},
+ {-1, -1, 1, -1},
+
+ {0, 0, 0, 0},
+ {1, 0, -1, -1},
+ {0, 1, -1, -1},
+ {1, 1, -1, -1},
+ {-1, 1, -1, -1},
+ {1, -1, -1, -1} };
+ unsigned sign_selector = get_bits(&gb, 6);
+ unsigned difference_selector = get_bits(&gb, 2);
+ y_base = 2 * get_bits(&gb, 5);
+ for (i = 0; i < 4; i++) {
+ y[i] = av_clip((int)y_base + offset_table[difference_selector] *
+ sign_table[sign_selector][i], 0, 63);
+ }
+ } else if (get_bits1(&gb)) {
+ if (get_bits1(&gb)) {
+ y_base = get_bits(&gb, 6);
+ } else {
+ unsigned adjust_index = get_bits(&gb, 3);
+ static const int8_t adjust[] = {-4, -3, -2, -1, 1, 2, 3, 4};
+ y_base = (y_base + adjust[adjust_index]) & 63;
+ }
+ for (i = 0; i < 4; i++)
+ y[i] = y_base;
+ }
+
+ if (get_bits1(&gb)) {
+ if (get_bits1(&gb)) {
+ cb = get_bits(&gb, 5);
+ cr = get_bits(&gb, 5);
+ } else {
+ unsigned adjust_index = get_bits(&gb, 3);
+ static const int8_t adjust[2][8] =
+ { { 1, 1, 0, -1, -1, -1, 0, 1 },
+ { 0, 1, 1, 1, 0, -1, -1, -1 } };
+ cb = (cb + adjust[0][adjust_index]) & 31;
+ cr = (cr + adjust[1][adjust_index]) & 31;
+ }
+ }
+ }
+ *yb++= y_base;
+
+ new_y[0] = y[0] * 4;
+ new_y[1] = y[1] * 4;
+ new_y[new_y_stride] = y[2] * 4;
+ new_y[new_y_stride + 1] = y[3] * 4;
+ *new_cb = cb * 8;
+ *new_cr = cr * 8;
+
+ if (old_y)
+ old_y += 2, old_cb++, old_cr++;
+ new_y += 2, new_cb++, new_cr++;
+ row_index++;
+ if (avctx->width / 2 == row_index) {
+ row_index = 0;
+ if (old_y) {
+ old_y += old_y_stride * 2 - avctx->width;
+ old_cb += old_cb_stride - avctx->width / 2;
+ old_cr += old_cr_stride - avctx->width / 2;
+ }
+ new_y += new_y_stride * 2 - avctx->width;
+ new_cb += new_cb_stride - avctx->width / 2;
+ new_cr += new_cr_stride - avctx->width / 2;
+ }
+
+ skip--;
+ }
+
+ av_log(avctx, AV_LOG_DEBUG,
+ "Escape sizes: %i, %i\n",
+ buf_size, get_bits_count(&gb) / 8);
+
+ if (s->frame.data[0])
+ avctx->release_buffer(avctx, &s->frame);
+
+ *(AVFrame*)data = s->frame = new_frame;
+ *data_size = sizeof(AVFrame);
+
+ return buf_size;
+}
+
+
+AVCodec ff_escape130_decoder = {
+ .name = "escape130",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_ESCAPE130,
+ .priv_data_size = sizeof(Escape130Context),
+ .init = escape130_decode_init,
+ .close = escape130_decode_close,
+ .decode = escape130_decode_frame,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("Escape 130"),
+};
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