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-rw-r--r--ffmpeg1/libavcodec/mmvideo.c238
1 files changed, 238 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/mmvideo.c b/ffmpeg1/libavcodec/mmvideo.c
new file mode 100644
index 0000000..bf47f65
--- /dev/null
+++ b/ffmpeg1/libavcodec/mmvideo.c
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+/*
+ * American Laser Games MM Video Decoder
+ * Copyright (c) 2006,2008 Peter Ross
+ *
+ * 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
+ * American Laser Games MM Video Decoder
+ * by Peter Ross (pross@xvid.org)
+ *
+ * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
+ * including Mad Dog McCree and Crime Patrol.
+ *
+ * Technical details here:
+ * http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+#define MM_PREAMBLE_SIZE 6
+
+#define MM_TYPE_INTER 0x5
+#define MM_TYPE_INTRA 0x8
+#define MM_TYPE_INTRA_HH 0xc
+#define MM_TYPE_INTER_HH 0xd
+#define MM_TYPE_INTRA_HHV 0xe
+#define MM_TYPE_INTER_HHV 0xf
+#define MM_TYPE_PALETTE 0x31
+
+typedef struct MmContext {
+ AVCodecContext *avctx;
+ AVFrame frame;
+ int palette[AVPALETTE_COUNT];
+ GetByteContext gb;
+} MmContext;
+
+static av_cold int mm_decode_init(AVCodecContext *avctx)
+{
+ MmContext *s = avctx->priv_data;
+
+ s->avctx = avctx;
+
+ avctx->pix_fmt = AV_PIX_FMT_PAL8;
+
+ avcodec_get_frame_defaults(&s->frame);
+
+ return 0;
+}
+
+static int mm_decode_pal(MmContext *s)
+{
+ int i;
+
+ bytestream2_skip(&s->gb, 4);
+ for (i = 0; i < 128; i++) {
+ s->palette[i] = 0xFFU << 24 | bytestream2_get_be24(&s->gb);
+ s->palette[i+128] = s->palette[i]<<2;
+ }
+
+ return 0;
+}
+
+/**
+ * @param half_horiz Half horizontal resolution (0 or 1)
+ * @param half_vert Half vertical resolution (0 or 1)
+ */
+static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert)
+{
+ int x = 0, y = 0;
+
+ while (bytestream2_get_bytes_left(&s->gb) > 0) {
+ int run_length, color;
+
+ if (y >= s->avctx->height)
+ return 0;
+
+ color = bytestream2_get_byte(&s->gb);
+ if (color & 0x80) {
+ run_length = 1;
+ }else{
+ run_length = (color & 0x7f) + 2;
+ color = bytestream2_get_byte(&s->gb);
+ }
+
+ if (half_horiz)
+ run_length *=2;
+
+ if (color) {
+ memset(s->frame.data[0] + y*s->frame.linesize[0] + x, color, run_length);
+ if (half_vert)
+ memset(s->frame.data[0] + (y+1)*s->frame.linesize[0] + x, color, run_length);
+ }
+ x+= run_length;
+
+ if (x >= s->avctx->width) {
+ x=0;
+ y += 1 + half_vert;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * @param half_horiz Half horizontal resolution (0 or 1)
+ * @param half_vert Half vertical resolution (0 or 1)
+ */
+static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
+{
+ int data_off = bytestream2_get_le16(&s->gb), y = 0;
+ GetByteContext data_ptr;
+
+ if (bytestream2_get_bytes_left(&s->gb) < data_off)
+ return AVERROR_INVALIDDATA;
+
+ bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
+ while (s->gb.buffer < data_ptr.buffer_start) {
+ int i, j;
+ int length = bytestream2_get_byte(&s->gb);
+ int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
+ length &= 0x7F;
+
+ if (length==0) {
+ y += x;
+ continue;
+ }
+
+ if (y + half_vert >= s->avctx->height)
+ return 0;
+
+ for(i=0; i<length; i++) {
+ int replace_array = bytestream2_get_byte(&s->gb);
+ for(j=0; j<8; j++) {
+ int replace = (replace_array >> (7-j)) & 1;
+ if (replace) {
+ int color = bytestream2_get_byte(&data_ptr);
+ s->frame.data[0][y*s->frame.linesize[0] + x] = color;
+ if (half_horiz)
+ s->frame.data[0][y*s->frame.linesize[0] + x + 1] = color;
+ if (half_vert) {
+ s->frame.data[0][(y+1)*s->frame.linesize[0] + x] = color;
+ if (half_horiz)
+ s->frame.data[0][(y+1)*s->frame.linesize[0] + x + 1] = color;
+ }
+ }
+ x += 1 + half_horiz;
+ }
+ }
+
+ y += 1 + half_vert;
+ }
+
+ return 0;
+}
+
+static int mm_decode_frame(AVCodecContext *avctx,
+ void *data, int *got_frame,
+ AVPacket *avpkt)
+{
+ const uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
+ MmContext *s = avctx->priv_data;
+ int type, res;
+
+ if (buf_size < MM_PREAMBLE_SIZE)
+ return AVERROR_INVALIDDATA;
+ type = AV_RL16(&buf[0]);
+ buf += MM_PREAMBLE_SIZE;
+ buf_size -= MM_PREAMBLE_SIZE;
+ bytestream2_init(&s->gb, buf, buf_size);
+
+ if ((res = ff_reget_buffer(avctx, &s->frame)) < 0)
+ return res;
+
+ switch(type) {
+ case MM_TYPE_PALETTE : res = mm_decode_pal(s); return avpkt->size;
+ case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break;
+ case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break;
+ case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break;
+ case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break;
+ case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break;
+ case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break;
+ default:
+ res = AVERROR_INVALIDDATA;
+ break;
+ }
+ if (res < 0)
+ return res;
+
+ memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
+
+ if ((res = av_frame_ref(data, &s->frame)) < 0)
+ return res;
+
+ *got_frame = 1;
+
+ return avpkt->size;
+}
+
+static av_cold int mm_decode_end(AVCodecContext *avctx)
+{
+ MmContext *s = avctx->priv_data;
+
+ av_frame_unref(&s->frame);
+
+ return 0;
+}
+
+AVCodec ff_mmvideo_decoder = {
+ .name = "mmvideo",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_MMVIDEO,
+ .priv_data_size = sizeof(MmContext),
+ .init = mm_decode_init,
+ .close = mm_decode_end,
+ .decode = mm_decode_frame,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
+};
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-06 16:34:36 +0000