FFmpeg/libavcodec/msvideo1.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

346 lines
11 KiB
C

/*
* Microsoft Video-1 Decoder
* Copyright (C) 2003 the ffmpeg project
*
* 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/msvideo1.c
* Microsoft Video-1 Decoder by Mike Melanson (melanson@pcisys.net)
* For more information about the MS Video-1 format, visit:
* http://www.pcisys.net/~melanson/codecs/
*
* This decoder outputs either PAL8 or RGB555 data, depending on the
* whether a RGB palette was passed through palctrl;
* if it's present, then the data is PAL8; RGB555 otherwise.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#define PALETTE_COUNT 256
#define CHECK_STREAM_PTR(n) \
if ((stream_ptr + n) > s->size ) { \
av_log(s->avctx, AV_LOG_ERROR, " MS Video-1 warning: stream_ptr out of bounds (%d >= %d)\n", \
stream_ptr + n, s->size); \
return; \
}
typedef struct Msvideo1Context {
AVCodecContext *avctx;
AVFrame frame;
const unsigned char *buf;
int size;
int mode_8bit; /* if it's not 8-bit, it's 16-bit */
} Msvideo1Context;
static av_cold int msvideo1_decode_init(AVCodecContext *avctx)
{
Msvideo1Context *s = avctx->priv_data;
s->avctx = avctx;
/* figure out the colorspace based on the presence of a palette */
if (s->avctx->palctrl) {
s->mode_8bit = 1;
avctx->pix_fmt = PIX_FMT_PAL8;
} else {
s->mode_8bit = 0;
avctx->pix_fmt = PIX_FMT_RGB555;
}
s->frame.data[0] = NULL;
return 0;
}
static void msvideo1_decode_8bit(Msvideo1Context *s)
{
int block_ptr, pixel_ptr;
int total_blocks;
int pixel_x, pixel_y; /* pixel width and height iterators */
int block_x, block_y; /* block width and height iterators */
int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
int block_inc;
int row_dec;
/* decoding parameters */
int stream_ptr;
unsigned char byte_a, byte_b;
unsigned short flags;
int skip_blocks;
unsigned char colors[8];
unsigned char *pixels = s->frame.data[0];
int stride = s->frame.linesize[0];
stream_ptr = 0;
skip_blocks = 0;
blocks_wide = s->avctx->width / 4;
blocks_high = s->avctx->height / 4;
total_blocks = blocks_wide * blocks_high;
block_inc = 4;
row_dec = stride + 4;
for (block_y = blocks_high; block_y > 0; block_y--) {
block_ptr = ((block_y * 4) - 1) * stride;
for (block_x = blocks_wide; block_x > 0; block_x--) {
/* check if this block should be skipped */
if (skip_blocks) {
block_ptr += block_inc;
skip_blocks--;
total_blocks--;
continue;
}
pixel_ptr = block_ptr;
/* get the next two bytes in the encoded data stream */
CHECK_STREAM_PTR(2);
byte_a = s->buf[stream_ptr++];
byte_b = s->buf[stream_ptr++];
/* check if the decode is finished */
if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0))
return;
else if ((byte_b & 0xFC) == 0x84) {
/* skip code, but don't count the current block */
skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
} else if (byte_b < 0x80) {
/* 2-color encoding */
flags = (byte_b << 8) | byte_a;
CHECK_STREAM_PTR(2);
colors[0] = s->buf[stream_ptr++];
colors[1] = s->buf[stream_ptr++];
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
pixel_ptr -= row_dec;
}
} else if (byte_b >= 0x90) {
/* 8-color encoding */
flags = (byte_b << 8) | byte_a;
CHECK_STREAM_PTR(8);
memcpy(colors, &s->buf[stream_ptr], 8);
stream_ptr += 8;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
pixels[pixel_ptr++] =
colors[((pixel_y & 0x2) << 1) +
(pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
pixel_ptr -= row_dec;
}
} else {
/* 1-color encoding */
colors[0] = byte_a;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++)
pixels[pixel_ptr++] = colors[0];
pixel_ptr -= row_dec;
}
}
block_ptr += block_inc;
total_blocks--;
}
}
/* make the palette available on the way out */
if (s->avctx->pix_fmt == PIX_FMT_PAL8) {
memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
if (s->avctx->palctrl->palette_changed) {
s->frame.palette_has_changed = 1;
s->avctx->palctrl->palette_changed = 0;
}
}
}
static void msvideo1_decode_16bit(Msvideo1Context *s)
{
int block_ptr, pixel_ptr;
int total_blocks;
int pixel_x, pixel_y; /* pixel width and height iterators */
int block_x, block_y; /* block width and height iterators */
int blocks_wide, blocks_high; /* width and height in 4x4 blocks */
int block_inc;
int row_dec;
/* decoding parameters */
int stream_ptr;
unsigned char byte_a, byte_b;
unsigned short flags;
int skip_blocks;
unsigned short colors[8];
unsigned short *pixels = (unsigned short *)s->frame.data[0];
int stride = s->frame.linesize[0] / 2;
stream_ptr = 0;
skip_blocks = 0;
blocks_wide = s->avctx->width / 4;
blocks_high = s->avctx->height / 4;
total_blocks = blocks_wide * blocks_high;
block_inc = 4;
row_dec = stride + 4;
for (block_y = blocks_high; block_y > 0; block_y--) {
block_ptr = ((block_y * 4) - 1) * stride;
for (block_x = blocks_wide; block_x > 0; block_x--) {
/* check if this block should be skipped */
if (skip_blocks) {
block_ptr += block_inc;
skip_blocks--;
total_blocks--;
continue;
}
pixel_ptr = block_ptr;
/* get the next two bytes in the encoded data stream */
CHECK_STREAM_PTR(2);
byte_a = s->buf[stream_ptr++];
byte_b = s->buf[stream_ptr++];
/* check if the decode is finished */
if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) {
return;
} else if ((byte_b & 0xFC) == 0x84) {
/* skip code, but don't count the current block */
skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1;
} else if (byte_b < 0x80) {
/* 2- or 8-color encoding modes */
flags = (byte_b << 8) | byte_a;
CHECK_STREAM_PTR(4);
colors[0] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
colors[1] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
if (colors[0] & 0x8000) {
/* 8-color encoding */
CHECK_STREAM_PTR(12);
colors[2] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
colors[3] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
colors[4] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
colors[5] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
colors[6] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
colors[7] = AV_RL16(&s->buf[stream_ptr]);
stream_ptr += 2;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
pixels[pixel_ptr++] =
colors[((pixel_y & 0x2) << 1) +
(pixel_x & 0x2) + ((flags & 0x1) ^ 1)];
pixel_ptr -= row_dec;
}
} else {
/* 2-color encoding */
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1)
pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1];
pixel_ptr -= row_dec;
}
}
} else {
/* otherwise, it's a 1-color block */
colors[0] = (byte_b << 8) | byte_a;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++)
pixels[pixel_ptr++] = colors[0];
pixel_ptr -= row_dec;
}
}
block_ptr += block_inc;
total_blocks--;
}
}
}
static int msvideo1_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
Msvideo1Context *s = avctx->priv_data;
s->buf = buf;
s->size = buf_size;
s->frame.reference = 1;
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, &s->frame)) {
av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
if (s->mode_8bit)
msvideo1_decode_8bit(s);
else
msvideo1_decode_16bit(s);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static av_cold int msvideo1_decode_end(AVCodecContext *avctx)
{
Msvideo1Context *s = avctx->priv_data;
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec msvideo1_decoder = {
"msvideo1",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_MSVIDEO1,
sizeof(Msvideo1Context),
msvideo1_decode_init,
NULL,
msvideo1_decode_end,
msvideo1_decode_frame,
CODEC_CAP_DR1,
.long_name= NULL_IF_CONFIG_SMALL("Microsoft Video 1"),
};