libavcodec/msvideo1.c - manifest_repos/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
  * 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/
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include "libavutil/internal.h"
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"
 #include "internal.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 */

     uint32_t pal[256];
 } Msvideo1Context;

 static av_cold int msvideo1_decode_init(AVCodecContext *avctx)
 {
     Msvideo1Context *s = avctx->priv_data;

     s->avctx = avctx;

     if (avctx->width < 4 || avctx->height < 4)
         return AVERROR_INVALIDDATA;

     /* figure out the colorspace based on the presence of a palette */
     if (s->avctx->bits_per_coded_sample == 8) {
         s->mode_8bit = 1;
         avctx->pix_fmt = AV_PIX_FMT_PAL8;
         if (avctx->extradata_size >= AVPALETTE_SIZE)
             memcpy(s->pal, avctx->extradata, AVPALETTE_SIZE);
     } else {
         s->mode_8bit = 0;
         avctx->pix_fmt = AV_PIX_FMT_RGB555;
     }

     s->frame = av_frame_alloc();
     if (!s->frame)
         return AVERROR(ENOMEM);

     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 == AV_PIX_FMT_PAL8)
         memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
 }

 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 *got_frame,
                                 AVPacket *avpkt)
 {
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     Msvideo1Context *s = avctx->priv_data;
     int ret;

     s->buf = buf;
     s->size = buf_size;

     // Discard frame if its smaller than the minimum frame size
     if (buf_size < (avctx->width/4) * (avctx->height/4) / 512) {
         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
         return AVERROR_INVALIDDATA;
     }

     if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
         return ret;

     if (s->mode_8bit) {
         int size;
         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &size);

         if (pal && size == AVPALETTE_SIZE) {
             memcpy(s->pal, pal, AVPALETTE_SIZE);
             s->frame->palette_has_changed = 1;
         } else if (pal) {
             av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);
         }
     }

     if (s->mode_8bit)
         msvideo1_decode_8bit(s);
     else
         msvideo1_decode_16bit(s);

     if ((ret = av_frame_ref(data, s->frame)) < 0)
         return ret;

     *got_frame      = 1;

     /* report that the buffer was completely consumed */
     return buf_size;
 }

 static av_cold int msvideo1_decode_end(AVCodecContext *avctx)
 {
     Msvideo1Context *s = avctx->priv_data;

     av_frame_free(&s->frame);

     return 0;
 }

 AVCodec ff_msvideo1_decoder = {
     .name           = "msvideo1",
     .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Video 1"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_MSVIDEO1,
     .priv_data_size = sizeof(Msvideo1Context),
     .init           = msvideo1_decode_init,
     .close          = msvideo1_decode_end,
     .decode         = msvideo1_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
 };
	/*
	* 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
	* 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/
	*/

	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include "libavutil/internal.h"
	#include "libavutil/intreadwrite.h"
	#include "avcodec.h"
	#include "internal.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 */

	uint32_t pal[256];
	} Msvideo1Context;

	static av_cold int msvideo1_decode_init(AVCodecContext *avctx)
	{
	Msvideo1Context *s = avctx->priv_data;

	s->avctx = avctx;

	if (avctx->width < 4 \|\| avctx->height < 4)
	return AVERROR_INVALIDDATA;

	/* figure out the colorspace based on the presence of a palette */
	if (s->avctx->bits_per_coded_sample == 8) {
	s->mode_8bit = 1;
	avctx->pix_fmt = AV_PIX_FMT_PAL8;
	if (avctx->extradata_size >= AVPALETTE_SIZE)
	memcpy(s->pal, avctx->extradata, AVPALETTE_SIZE);
	} else {
	s->mode_8bit = 0;
	avctx->pix_fmt = AV_PIX_FMT_RGB555;
	}

	s->frame = av_frame_alloc();
	if (!s->frame)
	return AVERROR(ENOMEM);

	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 == AV_PIX_FMT_PAL8)
	memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
	}

	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 got_frame,
	AVPacket *avpkt)
	{
	const uint8_t *buf = avpkt->data;
	int buf_size = avpkt->size;
	Msvideo1Context *s = avctx->priv_data;
	int ret;

	s->buf = buf;
	s->size = buf_size;

	// Discard frame if its smaller than the minimum frame size
	if (buf_size < (avctx->width/4) * (avctx->height/4) / 512) {
	av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
	return AVERROR_INVALIDDATA;
	}

	if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
	return ret;

	if (s->mode_8bit) {
	int size;
	const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &size);

	if (pal && size == AVPALETTE_SIZE) {
	memcpy(s->pal, pal, AVPALETTE_SIZE);
	s->frame->palette_has_changed = 1;
	} else if (pal) {
	av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);
	}
	}

	if (s->mode_8bit)
	msvideo1_decode_8bit(s);
	else
	msvideo1_decode_16bit(s);

	if ((ret = av_frame_ref(data, s->frame)) < 0)
	return ret;

	*got_frame = 1;

	/* report that the buffer was completely consumed */
	return buf_size;
	}

	static av_cold int msvideo1_decode_end(AVCodecContext *avctx)
	{
	Msvideo1Context *s = avctx->priv_data;

	av_frame_free(&s->frame);

	return 0;
	}

	AVCodec ff_msvideo1_decoder = {
	.name = "msvideo1",
	.long_name = NULL_IF_CONFIG_SMALL("Microsoft Video 1"),
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_MSVIDEO1,
	.priv_data_size = sizeof(Msvideo1Context),
	.init = msvideo1_decode_init,
	.close = msvideo1_decode_end,
	.decode = msvideo1_decode_frame,
	.capabilities = AV_CODEC_CAP_DR1,
	};