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

 /*
  * Tiertex Limited SEQ Video Decoder
  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.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
  */

 /**
  * @file
  * Tiertex Limited SEQ video decoder
  */

 #define BITSTREAM_READER_LE
 #include "avcodec.h"
 #include "get_bits.h"
 #include "internal.h"


 typedef struct SeqVideoContext {
     AVCodecContext *avctx;
     AVFrame *frame;
 } SeqVideoContext;


 static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
                                                  const unsigned char *src_end,
                                                  unsigned char *dst, int dst_size)
 {
     int i, len, sz;
     GetBitContext gb;
     int code_table[64];

     /* get the rle codes */
     init_get_bits(&gb, src, (src_end - src) * 8);
     for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
         if (get_bits_left(&gb) < 4)
             return NULL;
         code_table[i] = get_sbits(&gb, 4);
         sz += FFABS(code_table[i]);
     }
     src += (get_bits_count(&gb) + 7) / 8;

     /* do the rle unpacking */
     for (i = 0; i < 64 && dst_size > 0; i++) {
         len = code_table[i];
         if (len < 0) {
             len = -len;
             if (src_end - src < 1)
                 return NULL;
             memset(dst, *src++, FFMIN(len, dst_size));
         } else {
             if (src_end - src < len)
                 return NULL;
             memcpy(dst, src, FFMIN(len, dst_size));
             src += len;
         }
         dst += len;
         dst_size -= len;
     }
     return src;
 }

 static const unsigned char *seq_decode_op1(SeqVideoContext *seq,
                                            const unsigned char *src,
                                            const unsigned char *src_end,
                                            unsigned char *dst)
 {
     const unsigned char *color_table;
     int b, i, len, bits;
     GetBitContext gb;
     unsigned char block[8 * 8];

     if (src_end - src < 1)
         return NULL;
     len = *src++;
     if (len & 0x80) {
         switch (len & 3) {
         case 1:
             src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
             for (b = 0; b < 8; b++) {
                 memcpy(dst, &block[b * 8], 8);
                 dst += seq->frame->linesize[0];
             }
             break;
         case 2:
             src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
             for (i = 0; i < 8; i++) {
                 for (b = 0; b < 8; b++)
                     dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
                 ++dst;
             }
             break;
         }
     } else {
         if (len <= 0)
             return NULL;
         bits = ff_log2_tab[len - 1] + 1;
         if (src_end - src < len + 8 * bits)
             return NULL;
         color_table = src;
         src += len;
         init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
         for (b = 0; b < 8; b++) {
             for (i = 0; i < 8; i++)
                 dst[i] = color_table[get_bits(&gb, bits)];
             dst += seq->frame->linesize[0];
         }
     }

     return src;
 }

 static const unsigned char *seq_decode_op2(SeqVideoContext *seq,
                                            const unsigned char *src,
                                            const unsigned char *src_end,
                                            unsigned char *dst)
 {
     int i;

     if (src_end - src < 8 * 8)
         return NULL;

     for (i = 0; i < 8; i++) {
         memcpy(dst, src, 8);
         src += 8;
         dst += seq->frame->linesize[0];
     }

     return src;
 }

 static const unsigned char *seq_decode_op3(SeqVideoContext *seq,
                                            const unsigned char *src,
                                            const unsigned char *src_end,
                                            unsigned char *dst)
 {
     int pos, offset;

     do {
         if (src_end - src < 2)
             return NULL;
         pos = *src++;
         offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
         dst[offset] = *src++;
     } while (!(pos & 0x80));

     return src;
 }

 static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
 {
     const unsigned char *data_end = data + data_size;
     GetBitContext gb;
     int flags, i, j, x, y, op;
     unsigned char c[3];
     unsigned char *dst;
     uint32_t *palette;

     flags = *data++;

     if (flags & 1) {
         palette = (uint32_t *)seq->frame->data[1];
         if (data_end - data < 256 * 3)
             return AVERROR_INVALIDDATA;
         for (i = 0; i < 256; i++) {
             for (j = 0; j < 3; j++, data++)
                 c[j] = (*data << 2) | (*data >> 4);
             palette[i] = 0xFFU << 24 | AV_RB24(c);
         }
         seq->frame->palette_has_changed = 1;
     }

     if (flags & 2) {
         if (data_end - data < 128)
             return AVERROR_INVALIDDATA;
         init_get_bits(&gb, data, 128 * 8); data += 128;
         for (y = 0; y < 128; y += 8)
             for (x = 0; x < 256; x += 8) {
                 dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
                 op = get_bits(&gb, 2);
                 switch (op) {
                 case 1:
                     data = seq_decode_op1(seq, data, data_end, dst);
                     break;
                 case 2:
                     data = seq_decode_op2(seq, data, data_end, dst);
                     break;
                 case 3:
                     data = seq_decode_op3(seq, data, data_end, dst);
                     break;
                 }
                 if (!data)
                     return AVERROR_INVALIDDATA;
             }
     }
     return 0;
 }

 static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
 {
     SeqVideoContext *seq = avctx->priv_data;
     int ret;

     seq->avctx = avctx;
     avctx->pix_fmt = AV_PIX_FMT_PAL8;

     ret = ff_set_dimensions(avctx, 256, 128);
     if (ret < 0)
         return ret;

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

     return 0;
 }

 static int seqvideo_decode_frame(AVCodecContext *avctx,
                                  void *data, int *got_frame,
                                  AVPacket *avpkt)
 {
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     int ret;

     SeqVideoContext *seq = avctx->priv_data;

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

     if (seqvideo_decode(seq, buf, buf_size))
         return AVERROR_INVALIDDATA;

     if ((ret = av_frame_ref(data, seq->frame)) < 0)
         return ret;
     *got_frame       = 1;

     return buf_size;
 }

 static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
 {
     SeqVideoContext *seq = avctx->priv_data;

     av_frame_free(&seq->frame);

     return 0;
 }

 AVCodec ff_tiertexseqvideo_decoder = {
     .name           = "tiertexseqvideo",
     .long_name      = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_TIERTEXSEQVIDEO,
     .priv_data_size = sizeof(SeqVideoContext),
     .init           = seqvideo_decode_init,
     .close          = seqvideo_decode_end,
     .decode         = seqvideo_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
 };
	/*
	* Tiertex Limited SEQ Video Decoder
	* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.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
	*/

	/**
	* @file
	* Tiertex Limited SEQ video decoder
	*/

	#define BITSTREAM_READER_LE
	#include "avcodec.h"
	#include "get_bits.h"
	#include "internal.h"


	typedef struct SeqVideoContext {
	AVCodecContext *avctx;
	AVFrame *frame;
	} SeqVideoContext;


	static const unsigned char seq_unpack_rle_block(const unsigned char src,
	const unsigned char *src_end,
	unsigned char *dst, int dst_size)
	{
	int i, len, sz;
	GetBitContext gb;
	int code_table[64];

	/* get the rle codes */
	init_get_bits(&gb, src, (src_end - src) * 8);
	for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
	if (get_bits_left(&gb) < 4)
	return NULL;
	code_table[i] = get_sbits(&gb, 4);
	sz += FFABS(code_table[i]);
	}
	src += (get_bits_count(&gb) + 7) / 8;

	/* do the rle unpacking */
	for (i = 0; i < 64 && dst_size > 0; i++) {
	len = code_table[i];
	if (len < 0) {
	len = -len;
	if (src_end - src < 1)
	return NULL;
	memset(dst, *src++, FFMIN(len, dst_size));
	} else {
	if (src_end - src < len)
	return NULL;
	memcpy(dst, src, FFMIN(len, dst_size));
	src += len;
	}
	dst += len;
	dst_size -= len;
	}
	return src;
	}

	static const unsigned char seq_decode_op1(SeqVideoContext seq,
	const unsigned char *src,
	const unsigned char *src_end,
	unsigned char *dst)
	{
	const unsigned char *color_table;
	int b, i, len, bits;
	GetBitContext gb;
	unsigned char block[8 * 8];

	if (src_end - src < 1)
	return NULL;
	len = *src++;
	if (len & 0x80) {
	switch (len & 3) {
	case 1:
	src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
	for (b = 0; b < 8; b++) {
	memcpy(dst, &block[b * 8], 8);
	dst += seq->frame->linesize[0];
	}
	break;
	case 2:
	src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
	for (i = 0; i < 8; i++) {
	for (b = 0; b < 8; b++)
	dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
	++dst;
	}
	break;
	}
	} else {
	if (len <= 0)
	return NULL;
	bits = ff_log2_tab[len - 1] + 1;
	if (src_end - src < len + 8 * bits)
	return NULL;
	color_table = src;
	src += len;
	init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
	for (b = 0; b < 8; b++) {
	for (i = 0; i < 8; i++)
	dst[i] = color_table[get_bits(&gb, bits)];
	dst += seq->frame->linesize[0];
	}
	}

	return src;
	}

	static const unsigned char seq_decode_op2(SeqVideoContext seq,
	const unsigned char *src,
	const unsigned char *src_end,
	unsigned char *dst)
	{
	int i;

	if (src_end - src < 8 * 8)
	return NULL;

	for (i = 0; i < 8; i++) {
	memcpy(dst, src, 8);
	src += 8;
	dst += seq->frame->linesize[0];
	}

	return src;
	}

	static const unsigned char seq_decode_op3(SeqVideoContext seq,
	const unsigned char *src,
	const unsigned char *src_end,
	unsigned char *dst)
	{
	int pos, offset;

	do {
	if (src_end - src < 2)
	return NULL;
	pos = *src++;
	offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
	dst[offset] = *src++;
	} while (!(pos & 0x80));

	return src;
	}

	static int seqvideo_decode(SeqVideoContext seq, const unsigned char data, int data_size)
	{
	const unsigned char *data_end = data + data_size;
	GetBitContext gb;
	int flags, i, j, x, y, op;
	unsigned char c[3];
	unsigned char *dst;
	uint32_t *palette;

	flags = *data++;

	if (flags & 1) {
	palette = (uint32_t *)seq->frame->data[1];
	if (data_end - data < 256 * 3)
	return AVERROR_INVALIDDATA;
	for (i = 0; i < 256; i++) {
	for (j = 0; j < 3; j++, data++)
	c[j] = (data << 2) \| (data >> 4);
	palette[i] = 0xFFU << 24 \| AV_RB24(c);
	}
	seq->frame->palette_has_changed = 1;
	}

	if (flags & 2) {
	if (data_end - data < 128)
	return AVERROR_INVALIDDATA;
	init_get_bits(&gb, data, 128 * 8); data += 128;
	for (y = 0; y < 128; y += 8)
	for (x = 0; x < 256; x += 8) {
	dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
	op = get_bits(&gb, 2);
	switch (op) {
	case 1:
	data = seq_decode_op1(seq, data, data_end, dst);
	break;
	case 2:
	data = seq_decode_op2(seq, data, data_end, dst);
	break;
	case 3:
	data = seq_decode_op3(seq, data, data_end, dst);
	break;
	}
	if (!data)
	return AVERROR_INVALIDDATA;
	}
	}
	return 0;
	}

	static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
	{
	SeqVideoContext *seq = avctx->priv_data;
	int ret;

	seq->avctx = avctx;
	avctx->pix_fmt = AV_PIX_FMT_PAL8;

	ret = ff_set_dimensions(avctx, 256, 128);
	if (ret < 0)
	return ret;

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

	return 0;
	}

	static int seqvideo_decode_frame(AVCodecContext *avctx,
	void data, int got_frame,
	AVPacket *avpkt)
	{
	const uint8_t *buf = avpkt->data;
	int buf_size = avpkt->size;
	int ret;

	SeqVideoContext *seq = avctx->priv_data;

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

	if (seqvideo_decode(seq, buf, buf_size))
	return AVERROR_INVALIDDATA;

	if ((ret = av_frame_ref(data, seq->frame)) < 0)
	return ret;
	*got_frame = 1;

	return buf_size;
	}

	static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
	{
	SeqVideoContext *seq = avctx->priv_data;

	av_frame_free(&seq->frame);

	return 0;
	}

	AVCodec ff_tiertexseqvideo_decoder = {
	.name = "tiertexseqvideo",
	.long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_TIERTEXSEQVIDEO,
	.priv_data_size = sizeof(SeqVideoContext),
	.init = seqvideo_decode_init,
	.close = seqvideo_decode_end,
	.decode = seqvideo_decode_frame,
	.capabilities = AV_CODEC_CAP_DR1,
	};