From 4e114829b1d03ce4714c45f5d8628d46cc873cc0 Mon Sep 17 00:00:00 2001 From: Mike Melanson Date: Sun, 12 Feb 2006 06:49:40 +0000 Subject: complete American Laser Games MM playback system, courtesy of Peter Ross (suxen_drol at hotmail dot com) Originally committed as revision 4999 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/mmvideo.c | 204 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) create mode 100644 libavcodec/mmvideo.c (limited to 'libavcodec/mmvideo.c') diff --git a/libavcodec/mmvideo.c b/libavcodec/mmvideo.c new file mode 100644 index 0000000000..b2e146839d --- /dev/null +++ b/libavcodec/mmvideo.c @@ -0,0 +1,204 @@ +/* + * American Laser Games MM Video Decoder + * Copyright (c) 2006 Peter Ross + * + * 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 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/** + * @file mm.c + * American Laser Games MM Video Decoder + * by Peter Ross (suxen_drol at hotmail dot com) + * + * 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 "avcodec.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 + +typedef struct MmContext { + AVCodecContext *avctx; + AVFrame frame; +} MmContext; + +static int mm_decode_init(AVCodecContext *avctx) +{ + MmContext *s = avctx->priv_data; + + s->avctx = avctx; + + if (s->avctx->palctrl == NULL) { + av_log(avctx, AV_LOG_ERROR, "mmvideo: palette expected.\n"); + return -1; + } + + avctx->pix_fmt = PIX_FMT_PAL8; + avctx->has_b_frames = 0; + + if (avcodec_check_dimensions(avctx, avctx->width, avctx->height)) + return -1; + + s->frame.reference = 1; + if (avctx->get_buffer(avctx, &s->frame)) { + av_log(s->avctx, AV_LOG_ERROR, "mmvideo: get_buffer() failed\n"); + return -1; + } + + return 0; +} + +static void mm_decode_intra(MmContext * s, int half_horiz, int half_vert, const uint8_t *buf, int buf_size) +{ + int i, x, y; + i=0; x=0; y=0; + + while(iframe.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 += half_vert ? 2 : 1; + } + } +} + +static void mm_decode_inter(MmContext * s, int half_horiz, int half_vert, const uint8_t *buf, int buf_size) +{ + const int data_ptr = 2 + LE_16(&buf[0]); + int d, r, y; + d = data_ptr; r = 2; y = 0; + + while(r < data_ptr) { + int i, j; + int length = buf[r] & 0x7f; + int x = buf[r+1] + ((buf[r] & 0x80) << 1); + r += 2; + + if (length==0) { + y += x; + continue; + } + + for(i=0; i> (7-j)) & 1; + if (replace) { + int color = buf[d]; + 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; + } + d++; + } + x += half_horiz ? 2 : 1; + } + } + + r += length; + y += half_vert ? 2 : 1; + } +} + +static int mm_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + uint8_t *buf, int buf_size) +{ + MmContext *s = avctx->priv_data; + AVPaletteControl *palette_control = avctx->palctrl; + int type; + + if (palette_control->palette_changed) { + memcpy(s->frame.data[1], palette_control->palette, AVPALETTE_SIZE); + palette_control->palette_changed = 0; + } + + type = LE_16(&buf[0]); + buf += MM_PREAMBLE_SIZE; + buf_size -= MM_PREAMBLE_SIZE; + + switch(type) { + case MM_TYPE_INTRA : mm_decode_intra(s, 0, 0, buf, buf_size); break; + case MM_TYPE_INTRA_HH : mm_decode_intra(s, 1, 0, buf, buf_size); break; + case MM_TYPE_INTRA_HHV : mm_decode_intra(s, 1, 1, buf, buf_size); break; + case MM_TYPE_INTER : mm_decode_inter(s, 0, 0, buf, buf_size); break; + case MM_TYPE_INTER_HH : mm_decode_inter(s, 1, 0, buf, buf_size); break; + case MM_TYPE_INTER_HHV : mm_decode_inter(s, 1, 1, buf, buf_size); break; + default : + return -1; + } + + *data_size = sizeof(AVFrame); + *(AVFrame*)data = s->frame; + + return buf_size; +} + +static int mm_decode_end(AVCodecContext *avctx) +{ + MmContext *s = avctx->priv_data; + + if(s->frame.data[0]) + avctx->release_buffer(avctx, &s->frame); + + return 0; +} + +AVCodec mmvideo_decoder = { + "mmvideo", + CODEC_TYPE_VIDEO, + CODEC_ID_MMVIDEO, + sizeof(MmContext), + mm_decode_init, + NULL, + mm_decode_end, + mm_decode_frame, + CODEC_CAP_DR1, +}; -- cgit v1.2.3