libavcodec/msvideo1.c - vendor/opensource/ffmpeg - Git at Google

 /*
  * 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 <unistd.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,
                                 const uint8_t *buf, int buf_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",
     CODEC_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"),
 };
	/*
	* 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 <unistd.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,
	const uint8_t *buf, int buf_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",
	CODEC_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"),
	};