libavcodec/sgidec.c - third_party/ffmpeg - Git at Google

 /*
  * SGI image decoder
  * Todd Kirby <doubleshot@pacbell.net>
  *
  * 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
  */

 #include "libavutil/imgutils.h"
 #include "libavutil/avassert.h"
 #include "avcodec.h"
 #include "bytestream.h"
 #include "internal.h"
 #include "sgi.h"

 typedef struct SgiState {
     AVCodecContext *avctx;
     unsigned int width;
     unsigned int height;
     unsigned int depth;
     unsigned int bytes_per_channel;
     int linesize;
     GetByteContext g;
 } SgiState;

 /**
  * Expand an RLE row into a channel.
  * @param s the current image state
  * @param out_buf Points to one line after the output buffer.
  * @param len length of out_buf in bytes
  * @param pixelstride pixel stride of input buffer
  * @return size of output in bytes, else return error code.
  */
 static int expand_rle_row8(SgiState *s, uint8_t *out_buf,
                            int len, int pixelstride)
 {
     unsigned char pixel, count;
     unsigned char *orig = out_buf;
     uint8_t *out_end = out_buf + len;

     while (out_buf < out_end) {
         if (bytestream2_get_bytes_left(&s->g) < 1)
             return AVERROR_INVALIDDATA;
         pixel = bytestream2_get_byteu(&s->g);
         if (!(count = (pixel & 0x7f))) {
             break;
         }

         /* Check for buffer overflow. */
         if (out_end - out_buf <= pixelstride * (count - 1)) {
             av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
             return AVERROR_INVALIDDATA;
         }

         if (pixel & 0x80) {
             while (count--) {
                 *out_buf = bytestream2_get_byte(&s->g);
                 out_buf += pixelstride;
             }
         } else {
             pixel = bytestream2_get_byte(&s->g);

             while (count--) {
                 *out_buf = pixel;
                 out_buf += pixelstride;
             }
         }
     }
     return (out_buf - orig) / pixelstride;
 }

 static int expand_rle_row16(SgiState *s, uint16_t *out_buf,
                             int len, int pixelstride)
 {
     unsigned short pixel;
     unsigned char count;
     unsigned short *orig = out_buf;
     uint16_t *out_end = out_buf + len;

     while (out_buf < out_end) {
         if (bytestream2_get_bytes_left(&s->g) < 2)
             return AVERROR_INVALIDDATA;
         pixel = bytestream2_get_be16u(&s->g);
         if (!(count = (pixel & 0x7f)))
             break;

         /* Check for buffer overflow. */
         if (out_end - out_buf <= pixelstride * (count - 1)) {
             av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
             return AVERROR_INVALIDDATA;
         }

         if (pixel & 0x80) {
             while (count--) {
                 pixel = bytestream2_get_ne16(&s->g);
                 AV_WN16A(out_buf, pixel);
                 out_buf += pixelstride;
             }
         } else {
             pixel = bytestream2_get_ne16(&s->g);

             while (count--) {
                 AV_WN16A(out_buf, pixel);
                 out_buf += pixelstride;
             }
         }
     }
     return (out_buf - orig) / pixelstride;
 }


 /**
  * Read a run length encoded SGI image.
  * @param out_buf output buffer
  * @param s the current image state
  * @return 0 if no error, else return error code.
  */
 static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
 {
     uint8_t *dest_row;
     unsigned int len = s->height * s->depth * 4;
     GetByteContext g_table = s->g;
     unsigned int y, z;
     unsigned int start_offset;
     int linesize, ret;

     /* size of  RLE offset and length tables */
     if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
         return AVERROR_INVALIDDATA;
     }

     for (z = 0; z < s->depth; z++) {
         dest_row = out_buf;
         for (y = 0; y < s->height; y++) {
             linesize = s->width * s->depth;
             dest_row -= s->linesize;
             start_offset = bytestream2_get_be32(&g_table);
             bytestream2_seek(&s->g, start_offset, SEEK_SET);
             if (s->bytes_per_channel == 1)
                 ret = expand_rle_row8(s, dest_row + z, linesize, s->depth);
             else
                 ret = expand_rle_row16(s, (uint16_t *)dest_row + z, linesize, s->depth);
             if (ret != s->width)
                 return AVERROR_INVALIDDATA;
         }
     }
     return 0;
 }

 /**
  * Read an uncompressed SGI image.
  * @param out_buf output buffer
  * @param s the current image state
  * @return 0 if read success, else return error code.
  */
 static int read_uncompressed_sgi(unsigned char *out_buf, SgiState *s)
 {
     int x, y, z;
     unsigned int offset = s->height * s->width * s->bytes_per_channel;
     GetByteContext gp[4];
     uint8_t *out_end;

     /* Test buffer size. */
     if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
         return AVERROR_INVALIDDATA;

     /* Create a reader for each plane */
     for (z = 0; z < s->depth; z++) {
         gp[z] = s->g;
         bytestream2_skip(&gp[z], z * offset);
     }

     for (y = s->height - 1; y >= 0; y--) {
         out_end = out_buf + (y * s->linesize);
         if (s->bytes_per_channel == 1) {
             for (x = s->width; x > 0; x--)
                 for (z = 0; z < s->depth; z++)
                     *out_end++ = bytestream2_get_byteu(&gp[z]);
         } else {
             uint16_t *out16 = (uint16_t *)out_end;
             for (x = s->width; x > 0; x--)
                 for (z = 0; z < s->depth; z++)
                     *out16++ = bytestream2_get_ne16u(&gp[z]);
         }
     }
     return 0;
 }

 static int decode_frame(AVCodecContext *avctx,
                         void *data, int *got_frame,
                         AVPacket *avpkt)
 {
     SgiState *s = avctx->priv_data;
     AVFrame *p = data;
     unsigned int dimension, rle;
     int ret = 0;
     uint8_t *out_buf, *out_end;

     bytestream2_init(&s->g, avpkt->data, avpkt->size);
     if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
         av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
         return AVERROR_INVALIDDATA;
     }

     /* Test for SGI magic. */
     if (bytestream2_get_be16u(&s->g) != SGI_MAGIC) {
         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
         return AVERROR_INVALIDDATA;
     }

     rle                  = bytestream2_get_byteu(&s->g);
     s->bytes_per_channel = bytestream2_get_byteu(&s->g);
     dimension            = bytestream2_get_be16u(&s->g);
     s->width             = bytestream2_get_be16u(&s->g);
     s->height            = bytestream2_get_be16u(&s->g);
     s->depth             = bytestream2_get_be16u(&s->g);

     if (s->bytes_per_channel != 1 && s->bytes_per_channel != 2) {
         av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
         return AVERROR_INVALIDDATA;
     }

     /* Check for supported image dimensions. */
     if (dimension != 2 && dimension != 3) {
         av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
         return AVERROR_INVALIDDATA;
     }

     if (s->depth == SGI_GRAYSCALE) {
         avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
     } else if (s->depth == SGI_RGB) {
         avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
     } else if (s->depth == SGI_RGBA) {
         avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA;
     } else {
         av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
         return AVERROR_INVALIDDATA;
     }

     ret = ff_set_dimensions(avctx, s->width, s->height);
     if (ret < 0)
         return ret;

     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
         return ret;

     p->pict_type = AV_PICTURE_TYPE_I;
     p->key_frame = 1;
     out_buf = p->data[0];

     out_end = out_buf + p->linesize[0] * s->height;

     s->linesize = p->linesize[0];

     /* Skip header. */
     bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
     if (rle) {
         ret = read_rle_sgi(out_end, s);
     } else {
         ret = read_uncompressed_sgi(out_buf, s);
     }
     if (ret)
         return ret;

     *got_frame = 1;
     return avpkt->size;
 }

 static av_cold int sgi_decode_init(AVCodecContext *avctx)
 {
     SgiState *s = avctx->priv_data;

     s->avctx = avctx;

     return 0;
 }

 AVCodec ff_sgi_decoder = {
     .name           = "sgi",
     .long_name      = NULL_IF_CONFIG_SMALL("SGI image"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_SGI,
     .priv_data_size = sizeof(SgiState),
     .decode         = decode_frame,
     .init           = sgi_decode_init,
     .capabilities   = AV_CODEC_CAP_DR1,
 };
	/*
	* SGI image decoder
	* Todd Kirby <doubleshot@pacbell.net>
	*
	* 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
	*/

	#include "libavutil/imgutils.h"
	#include "libavutil/avassert.h"
	#include "avcodec.h"
	#include "bytestream.h"
	#include "internal.h"
	#include "sgi.h"

	typedef struct SgiState {
	AVCodecContext *avctx;
	unsigned int width;
	unsigned int height;
	unsigned int depth;
	unsigned int bytes_per_channel;
	int linesize;
	GetByteContext g;
	} SgiState;

	/**
	* Expand an RLE row into a channel.
	* @param s the current image state
	* @param out_buf Points to one line after the output buffer.
	* @param len length of out_buf in bytes
	* @param pixelstride pixel stride of input buffer
	* @return size of output in bytes, else return error code.
	*/
	static int expand_rle_row8(SgiState s, uint8_t out_buf,
	int len, int pixelstride)
	{
	unsigned char pixel, count;
	unsigned char *orig = out_buf;
	uint8_t *out_end = out_buf + len;

	while (out_buf < out_end) {
	if (bytestream2_get_bytes_left(&s->g) < 1)
	return AVERROR_INVALIDDATA;
	pixel = bytestream2_get_byteu(&s->g);
	if (!(count = (pixel & 0x7f))) {
	break;
	}

	/* Check for buffer overflow. */
	if (out_end - out_buf <= pixelstride * (count - 1)) {
	av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
	return AVERROR_INVALIDDATA;
	}

	if (pixel & 0x80) {
	while (count--) {
	*out_buf = bytestream2_get_byte(&s->g);
	out_buf += pixelstride;
	}
	} else {
	pixel = bytestream2_get_byte(&s->g);

	while (count--) {
	*out_buf = pixel;
	out_buf += pixelstride;
	}
	}
	}
	return (out_buf - orig) / pixelstride;
	}

	static int expand_rle_row16(SgiState s, uint16_t out_buf,
	int len, int pixelstride)
	{
	unsigned short pixel;
	unsigned char count;
	unsigned short *orig = out_buf;
	uint16_t *out_end = out_buf + len;

	while (out_buf < out_end) {
	if (bytestream2_get_bytes_left(&s->g) < 2)
	return AVERROR_INVALIDDATA;
	pixel = bytestream2_get_be16u(&s->g);
	if (!(count = (pixel & 0x7f)))
	break;

	/* Check for buffer overflow. */
	if (out_end - out_buf <= pixelstride * (count - 1)) {
	av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
	return AVERROR_INVALIDDATA;
	}

	if (pixel & 0x80) {
	while (count--) {
	pixel = bytestream2_get_ne16(&s->g);
	AV_WN16A(out_buf, pixel);
	out_buf += pixelstride;
	}
	} else {
	pixel = bytestream2_get_ne16(&s->g);

	while (count--) {
	AV_WN16A(out_buf, pixel);
	out_buf += pixelstride;
	}
	}
	}
	return (out_buf - orig) / pixelstride;
	}


	/**
	* Read a run length encoded SGI image.
	* @param out_buf output buffer
	* @param s the current image state
	* @return 0 if no error, else return error code.
	*/
	static int read_rle_sgi(uint8_t out_buf, SgiState s)
	{
	uint8_t *dest_row;
	unsigned int len = s->height * s->depth * 4;
	GetByteContext g_table = s->g;
	unsigned int y, z;
	unsigned int start_offset;
	int linesize, ret;

	/* size of RLE offset and length tables */
	if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
	return AVERROR_INVALIDDATA;
	}

	for (z = 0; z < s->depth; z++) {
	dest_row = out_buf;
	for (y = 0; y < s->height; y++) {
	linesize = s->width * s->depth;
	dest_row -= s->linesize;
	start_offset = bytestream2_get_be32(&g_table);
	bytestream2_seek(&s->g, start_offset, SEEK_SET);
	if (s->bytes_per_channel == 1)
	ret = expand_rle_row8(s, dest_row + z, linesize, s->depth);
	else
	ret = expand_rle_row16(s, (uint16_t *)dest_row + z, linesize, s->depth);
	if (ret != s->width)
	return AVERROR_INVALIDDATA;
	}
	}
	return 0;
	}

	/**
	* Read an uncompressed SGI image.
	* @param out_buf output buffer
	* @param s the current image state
	* @return 0 if read success, else return error code.
	*/
	static int read_uncompressed_sgi(unsigned char out_buf, SgiState s)
	{
	int x, y, z;
	unsigned int offset = s->height * s->width * s->bytes_per_channel;
	GetByteContext gp[4];
	uint8_t *out_end;

	/* Test buffer size. */
	if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
	return AVERROR_INVALIDDATA;

	/* Create a reader for each plane */
	for (z = 0; z < s->depth; z++) {
	gp[z] = s->g;
	bytestream2_skip(&gp[z], z * offset);
	}

	for (y = s->height - 1; y >= 0; y--) {
	out_end = out_buf + (y * s->linesize);
	if (s->bytes_per_channel == 1) {
	for (x = s->width; x > 0; x--)
	for (z = 0; z < s->depth; z++)
	*out_end++ = bytestream2_get_byteu(&gp[z]);
	} else {
	uint16_t out16 = (uint16_t )out_end;
	for (x = s->width; x > 0; x--)
	for (z = 0; z < s->depth; z++)
	*out16++ = bytestream2_get_ne16u(&gp[z]);
	}
	}
	return 0;
	}

	static int decode_frame(AVCodecContext *avctx,
	void data, int got_frame,
	AVPacket *avpkt)
	{
	SgiState *s = avctx->priv_data;
	AVFrame *p = data;
	unsigned int dimension, rle;
	int ret = 0;
	uint8_t out_buf, out_end;

	bytestream2_init(&s->g, avpkt->data, avpkt->size);
	if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
	av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
	return AVERROR_INVALIDDATA;
	}

	/* Test for SGI magic. */
	if (bytestream2_get_be16u(&s->g) != SGI_MAGIC) {
	av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
	return AVERROR_INVALIDDATA;
	}

	rle = bytestream2_get_byteu(&s->g);
	s->bytes_per_channel = bytestream2_get_byteu(&s->g);
	dimension = bytestream2_get_be16u(&s->g);
	s->width = bytestream2_get_be16u(&s->g);
	s->height = bytestream2_get_be16u(&s->g);
	s->depth = bytestream2_get_be16u(&s->g);

	if (s->bytes_per_channel != 1 && s->bytes_per_channel != 2) {
	av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
	return AVERROR_INVALIDDATA;
	}

	/* Check for supported image dimensions. */
	if (dimension != 2 && dimension != 3) {
	av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
	return AVERROR_INVALIDDATA;
	}

	if (s->depth == SGI_GRAYSCALE) {
	avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
	} else if (s->depth == SGI_RGB) {
	avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
	} else if (s->depth == SGI_RGBA) {
	avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA;
	} else {
	av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
	return AVERROR_INVALIDDATA;
	}

	ret = ff_set_dimensions(avctx, s->width, s->height);
	if (ret < 0)
	return ret;

	if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
	return ret;

	p->pict_type = AV_PICTURE_TYPE_I;
	p->key_frame = 1;
	out_buf = p->data[0];

	out_end = out_buf + p->linesize[0] * s->height;

	s->linesize = p->linesize[0];

	/* Skip header. */
	bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
	if (rle) {
	ret = read_rle_sgi(out_end, s);
	} else {
	ret = read_uncompressed_sgi(out_buf, s);
	}
	if (ret)
	return ret;

	*got_frame = 1;
	return avpkt->size;
	}

	static av_cold int sgi_decode_init(AVCodecContext *avctx)
	{
	SgiState *s = avctx->priv_data;

	s->avctx = avctx;

	return 0;
	}

	AVCodec ff_sgi_decoder = {
	.name = "sgi",
	.long_name = NULL_IF_CONFIG_SMALL("SGI image"),
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_SGI,
	.priv_data_size = sizeof(SgiState),
	.decode = decode_frame,
	.init = sgi_decode_init,
	.capabilities = AV_CODEC_CAP_DR1,
	};