Index: patched-ffmpeg-mt/libavcodec/kgv1dec.c |
=================================================================== |
--- patched-ffmpeg-mt/libavcodec/kgv1dec.c (revision 0) |
+++ patched-ffmpeg-mt/libavcodec/kgv1dec.c (revision 0) |
@@ -0,0 +1,176 @@ |
+/* |
+ * Kega Game Video (KGV1) decoder |
+ * Copyright (c) 2010 Daniel Verkamp |
+ * |
+ * 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 libavcodec/kgv1dec.c |
+ * Kega Game Video decoder |
+ */ |
+ |
+#include "libavutil/intreadwrite.h" |
+#include "avcodec.h" |
+ |
+typedef struct { |
+ AVCodecContext *avctx; |
+ AVFrame pic; |
+ uint16_t *prev, *cur; |
+} KgvContext; |
+ |
+static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) |
+{ |
+ const uint8_t *buf = avpkt->data; |
+ const uint8_t *buf_end = buf + avpkt->size; |
+ KgvContext * const c = avctx->priv_data; |
+ int offsets[7]; |
+ uint16_t *out, *prev; |
+ int outcnt = 0, maxcnt; |
+ int w, h, i; |
+ |
+ if (avpkt->size < 2) |
+ return -1; |
+ |
+ w = (buf[0] + 1) * 8; |
+ h = (buf[1] + 1) * 8; |
+ buf += 2; |
+ |
+ if (avcodec_check_dimensions(avctx, w, h)) |
+ return -1; |
+ |
+ if (w != avctx->width || h != avctx->height) |
+ avcodec_set_dimensions(avctx, w, h); |
+ |
+ maxcnt = w * h; |
+ |
+ out = av_realloc(c->cur, w * h * 2); |
+ if (!out) |
+ return -1; |
+ c->cur = out; |
+ |
+ prev = av_realloc(c->prev, w * h * 2); |
+ if (!prev) |
+ return -1; |
+ c->prev = prev; |
+ |
+ for (i = 0; i < 7; i++) |
+ offsets[i] = -1; |
+ |
+ while (outcnt < maxcnt && buf_end - 2 > buf) { |
+ int code = AV_RL16(buf); |
+ buf += 2; |
+ |
+ if (!(code & 0x8000)) { |
+ out[outcnt++] = code; // rgb555 pixel coded directly |
+ } else { |
+ int count; |
+ uint16_t *inp; |
+ |
+ if ((code & 0x6000) == 0x6000) { |
+ // copy from previous frame |
+ int oidx = (code >> 10) & 7; |
+ int start; |
+ |
+ count = (code & 0x3FF) + 3; |
+ |
+ if (offsets[oidx] < 0) { |
+ if (buf_end - 3 < buf) |
+ break; |
+ offsets[oidx] = AV_RL24(buf); |
+ buf += 3; |
+ } |
+ |
+ start = (outcnt + offsets[oidx]) % maxcnt; |
+ |
+ if (maxcnt - start < count) |
+ break; |
+ |
+ inp = prev + start; |
+ } else { |
+ // copy from earlier in this frame |
+ int offset = (code & 0x1FFF) + 1; |
+ |
+ if (!(code & 0x6000)) { |
+ count = 2; |
+ } else if ((code & 0x6000) == 0x2000) { |
+ count = 3; |
+ } else { |
+ if (buf_end - 1 < buf) |
+ break; |
+ count = 4 + *buf++; |
+ } |
+ |
+ if (outcnt < offset) |
+ break; |
+ |
+ inp = out + outcnt - offset; |
+ } |
+ |
+ if (maxcnt - outcnt < count) |
+ break; |
+ |
+ for (i = 0; i < count; i++) |
+ out[outcnt++] = inp[i]; |
+ } |
+ } |
+ |
+ if (outcnt - maxcnt) |
+ av_log(avctx, AV_LOG_DEBUG, "frame finished with %d diff\n", outcnt - maxcnt); |
+ |
+ c->pic.data[0] = (uint8_t *)c->cur; |
+ c->pic.linesize[0] = w * 2; |
+ |
+ *data_size = sizeof(AVFrame); |
+ *(AVFrame*)data = c->pic; |
+ |
+ FFSWAP(uint16_t *, c->cur, c->prev); |
+ |
+ return avpkt->size; |
+} |
+ |
+static av_cold int decode_init(AVCodecContext *avctx) |
+{ |
+ KgvContext * const c = avctx->priv_data; |
+ |
+ c->avctx = avctx; |
+ avctx->pix_fmt = PIX_FMT_RGB555; |
+ |
+ return 0; |
+} |
+ |
+static av_cold int decode_end(AVCodecContext *avctx) |
+{ |
+ KgvContext * const c = avctx->priv_data; |
+ |
+ av_freep(&c->cur); |
+ av_freep(&c->prev); |
+ |
+ return 0; |
+} |
+ |
+AVCodec kgv1_decoder = { |
+ "kgv1", |
+ CODEC_TYPE_VIDEO, |
+ CODEC_ID_KGV1, |
+ sizeof(KgvContext), |
+ decode_init, |
+ NULL, |
+ decode_end, |
+ decode_frame, |
+ .long_name = NULL_IF_CONFIG_SMALL("Kega Game Video"), |
+}; |