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348 lines
11 KiB
348 lines
11 KiB
/* |
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* Microsoft Video-1 Decoder |
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* Copyright (C) 2003 the ffmpeg project |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* Microsoft Video-1 Decoder by Mike Melanson (melanson@pcisys.net) |
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* For more information about the MS Video-1 format, visit: |
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* http://www.pcisys.net/~melanson/codecs/ |
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* |
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*/ |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include "libavutil/internal.h" |
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#include "libavutil/intreadwrite.h" |
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#include "avcodec.h" |
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#include "internal.h" |
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#define PALETTE_COUNT 256 |
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#define CHECK_STREAM_PTR(n) \ |
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if ((stream_ptr + n) > s->size ) { \ |
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av_log(s->avctx, AV_LOG_ERROR, " MS Video-1 warning: stream_ptr out of bounds (%d >= %d)\n", \ |
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stream_ptr + n, s->size); \ |
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return; \ |
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} |
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typedef struct Msvideo1Context { |
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AVCodecContext *avctx; |
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AVFrame frame; |
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const unsigned char *buf; |
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int size; |
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int mode_8bit; /* if it's not 8-bit, it's 16-bit */ |
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uint32_t pal[256]; |
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} Msvideo1Context; |
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static av_cold int msvideo1_decode_init(AVCodecContext *avctx) |
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{ |
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Msvideo1Context *s = avctx->priv_data; |
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s->avctx = avctx; |
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/* figure out the colorspace based on the presence of a palette */ |
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if (s->avctx->bits_per_coded_sample == 8) { |
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s->mode_8bit = 1; |
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avctx->pix_fmt = AV_PIX_FMT_PAL8; |
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} else { |
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s->mode_8bit = 0; |
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avctx->pix_fmt = AV_PIX_FMT_RGB555; |
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} |
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avcodec_get_frame_defaults(&s->frame); |
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return 0; |
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} |
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static void msvideo1_decode_8bit(Msvideo1Context *s) |
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{ |
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int block_ptr, pixel_ptr; |
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int total_blocks; |
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int pixel_x, pixel_y; /* pixel width and height iterators */ |
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int block_x, block_y; /* block width and height iterators */ |
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int blocks_wide, blocks_high; /* width and height in 4x4 blocks */ |
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int block_inc; |
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int row_dec; |
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/* decoding parameters */ |
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int stream_ptr; |
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unsigned char byte_a, byte_b; |
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unsigned short flags; |
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int skip_blocks; |
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unsigned char colors[8]; |
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unsigned char *pixels = s->frame.data[0]; |
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int stride = s->frame.linesize[0]; |
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stream_ptr = 0; |
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skip_blocks = 0; |
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blocks_wide = s->avctx->width / 4; |
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blocks_high = s->avctx->height / 4; |
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total_blocks = blocks_wide * blocks_high; |
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block_inc = 4; |
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row_dec = stride + 4; |
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for (block_y = blocks_high; block_y > 0; block_y--) { |
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block_ptr = ((block_y * 4) - 1) * stride; |
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for (block_x = blocks_wide; block_x > 0; block_x--) { |
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/* check if this block should be skipped */ |
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if (skip_blocks) { |
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block_ptr += block_inc; |
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skip_blocks--; |
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total_blocks--; |
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continue; |
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} |
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pixel_ptr = block_ptr; |
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/* get the next two bytes in the encoded data stream */ |
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CHECK_STREAM_PTR(2); |
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byte_a = s->buf[stream_ptr++]; |
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byte_b = s->buf[stream_ptr++]; |
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/* check if the decode is finished */ |
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if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) |
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return; |
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else if ((byte_b & 0xFC) == 0x84) { |
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/* skip code, but don't count the current block */ |
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skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1; |
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} else if (byte_b < 0x80) { |
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/* 2-color encoding */ |
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flags = (byte_b << 8) | byte_a; |
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CHECK_STREAM_PTR(2); |
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colors[0] = s->buf[stream_ptr++]; |
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colors[1] = s->buf[stream_ptr++]; |
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for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
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for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
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pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1]; |
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pixel_ptr -= row_dec; |
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} |
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} else if (byte_b >= 0x90) { |
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/* 8-color encoding */ |
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flags = (byte_b << 8) | byte_a; |
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CHECK_STREAM_PTR(8); |
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memcpy(colors, &s->buf[stream_ptr], 8); |
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stream_ptr += 8; |
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for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
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for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
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pixels[pixel_ptr++] = |
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colors[((pixel_y & 0x2) << 1) + |
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(pixel_x & 0x2) + ((flags & 0x1) ^ 1)]; |
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pixel_ptr -= row_dec; |
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} |
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} else { |
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/* 1-color encoding */ |
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colors[0] = byte_a; |
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for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
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for (pixel_x = 0; pixel_x < 4; pixel_x++) |
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pixels[pixel_ptr++] = colors[0]; |
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pixel_ptr -= row_dec; |
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} |
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} |
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block_ptr += block_inc; |
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total_blocks--; |
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} |
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} |
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/* make the palette available on the way out */ |
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if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8) |
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memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE); |
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} |
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static void msvideo1_decode_16bit(Msvideo1Context *s) |
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{ |
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int block_ptr, pixel_ptr; |
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int total_blocks; |
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int pixel_x, pixel_y; /* pixel width and height iterators */ |
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int block_x, block_y; /* block width and height iterators */ |
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int blocks_wide, blocks_high; /* width and height in 4x4 blocks */ |
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int block_inc; |
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int row_dec; |
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/* decoding parameters */ |
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int stream_ptr; |
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unsigned char byte_a, byte_b; |
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unsigned short flags; |
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int skip_blocks; |
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unsigned short colors[8]; |
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unsigned short *pixels = (unsigned short *)s->frame.data[0]; |
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int stride = s->frame.linesize[0] / 2; |
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stream_ptr = 0; |
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skip_blocks = 0; |
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blocks_wide = s->avctx->width / 4; |
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blocks_high = s->avctx->height / 4; |
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total_blocks = blocks_wide * blocks_high; |
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block_inc = 4; |
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row_dec = stride + 4; |
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for (block_y = blocks_high; block_y > 0; block_y--) { |
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block_ptr = ((block_y * 4) - 1) * stride; |
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for (block_x = blocks_wide; block_x > 0; block_x--) { |
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/* check if this block should be skipped */ |
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if (skip_blocks) { |
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block_ptr += block_inc; |
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skip_blocks--; |
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total_blocks--; |
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continue; |
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} |
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pixel_ptr = block_ptr; |
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/* get the next two bytes in the encoded data stream */ |
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CHECK_STREAM_PTR(2); |
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byte_a = s->buf[stream_ptr++]; |
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byte_b = s->buf[stream_ptr++]; |
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/* check if the decode is finished */ |
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if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) { |
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return; |
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} else if ((byte_b & 0xFC) == 0x84) { |
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/* skip code, but don't count the current block */ |
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skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1; |
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} else if (byte_b < 0x80) { |
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/* 2- or 8-color encoding modes */ |
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flags = (byte_b << 8) | byte_a; |
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CHECK_STREAM_PTR(4); |
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colors[0] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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colors[1] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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if (colors[0] & 0x8000) { |
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/* 8-color encoding */ |
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CHECK_STREAM_PTR(12); |
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colors[2] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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colors[3] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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colors[4] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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colors[5] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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colors[6] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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colors[7] = AV_RL16(&s->buf[stream_ptr]); |
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stream_ptr += 2; |
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for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
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for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
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pixels[pixel_ptr++] = |
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colors[((pixel_y & 0x2) << 1) + |
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(pixel_x & 0x2) + ((flags & 0x1) ^ 1)]; |
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pixel_ptr -= row_dec; |
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} |
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} else { |
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/* 2-color encoding */ |
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for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
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for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
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pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1]; |
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pixel_ptr -= row_dec; |
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} |
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} |
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} else { |
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/* otherwise, it's a 1-color block */ |
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colors[0] = (byte_b << 8) | byte_a; |
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for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
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for (pixel_x = 0; pixel_x < 4; pixel_x++) |
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pixels[pixel_ptr++] = colors[0]; |
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pixel_ptr -= row_dec; |
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} |
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} |
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block_ptr += block_inc; |
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total_blocks--; |
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} |
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} |
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} |
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static int msvideo1_decode_frame(AVCodecContext *avctx, |
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void *data, int *got_frame, |
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AVPacket *avpkt) |
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{ |
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const uint8_t *buf = avpkt->data; |
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int buf_size = avpkt->size; |
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Msvideo1Context *s = avctx->priv_data; |
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int ret; |
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s->buf = buf; |
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s->size = buf_size; |
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if ((ret = ff_reget_buffer(avctx, &s->frame)) < 0) { |
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av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); |
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return ret; |
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} |
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if (s->mode_8bit) { |
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const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); |
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if (pal) { |
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memcpy(s->pal, pal, AVPALETTE_SIZE); |
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s->frame.palette_has_changed = 1; |
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} |
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} |
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if (s->mode_8bit) |
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msvideo1_decode_8bit(s); |
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else |
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msvideo1_decode_16bit(s); |
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if ((ret = av_frame_ref(data, &s->frame)) < 0) |
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return ret; |
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*got_frame = 1; |
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/* report that the buffer was completely consumed */ |
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return buf_size; |
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} |
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static av_cold int msvideo1_decode_end(AVCodecContext *avctx) |
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{ |
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Msvideo1Context *s = avctx->priv_data; |
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av_frame_unref(&s->frame); |
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return 0; |
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} |
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AVCodec ff_msvideo1_decoder = { |
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.name = "msvideo1", |
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.long_name = NULL_IF_CONFIG_SMALL("Microsoft Video 1"), |
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.type = AVMEDIA_TYPE_VIDEO, |
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.id = AV_CODEC_ID_MSVIDEO1, |
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.priv_data_size = sizeof(Msvideo1Context), |
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.init = msvideo1_decode_init, |
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.close = msvideo1_decode_end, |
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.decode = msvideo1_decode_frame, |
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.capabilities = CODEC_CAP_DR1, |
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};
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