/*
  * Flash Screen Video decoder
  * Copyright (C) 2004 Alex Beregszaszi
  * Copyright (C) 2006 Benjamin Larsson
  *

  * 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

  * Flash Screen Video decoder
  * @author Alex Beregszaszi
  * @author Benjamin Larsson

  * @author Daniel Verkamp
  * @author Konstantin Shishkov

  *

  * A description of the bitstream format for Flash Screen Video version 1/2
  * is part of the SWF File Format Specification (version 10), which can be
  * downloaded from http://www.adobe.com/devnet/swf.html.

  */
 
 #include <stdio.h>
 #include <stdlib.h>

 #include <zlib.h>

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"

 #include "bytestream.h"

 #include "get_bits.h"

 #include "internal.h"

 typedef struct BlockInfo {
     uint8_t *pos;
     int      size;
 } BlockInfo;
 

 typedef struct FlashSVContext {
     AVCodecContext *avctx;

     AVFrame        *frame;

     int             image_width, image_height;
     int             block_width, block_height;
     uint8_t        *tmpblock;
     int             block_size;
     z_stream        zstream;

     int             ver;
     const uint32_t *pal;
     int             is_keyframe;
     uint8_t        *keyframedata;
     uint8_t        *keyframe;
     BlockInfo      *blocks;
     uint8_t        *deflate_block;
     int             deflate_block_size;
     int             color_depth;
     int             zlibprime_curr, zlibprime_prev;
     int             diff_start, diff_height;

 } FlashSVContext;
 

 static int decode_hybrid(const uint8_t *sptr, const uint8_t *sptr_end, uint8_t *dptr, int dx, int dy,

                          int h, int w, int stride, const uint32_t *pal)
 {
     int x, y;
     const uint8_t *orig_src = sptr;
 

     for (y = dx + h; y > dx; y--) {

         uint8_t *dst = dptr + (y * stride) + dy * 3;
         for (x = 0; x < w; x++) {

             if (sptr >= sptr_end)
                 return AVERROR_INVALIDDATA;

             if (*sptr & 0x80) {
                 /* 15-bit color */
                 unsigned c = AV_RB16(sptr) & ~0x8000;
                 unsigned b =  c        & 0x1F;
                 unsigned g = (c >>  5) & 0x1F;
                 unsigned r =  c >> 10;
                 /* 000aaabb -> aaabbaaa  */
                 *dst++ = (b << 3) | (b >> 2);
                 *dst++ = (g << 3) | (g >> 2);
                 *dst++ = (r << 3) | (r >> 2);
                 sptr += 2;
             } else {
                 /* palette index */
                 uint32_t c = pal[*sptr++];
                 bytestream_put_le24(&dst, c);
             }
         }
     }
     return sptr - orig_src;
 }
 

 static av_cold int flashsv_decode_end(AVCodecContext *avctx)
 {
     FlashSVContext *s = avctx->priv_data;
     inflateEnd(&s->zstream);
     /* release the frame if needed */
     av_frame_free(&s->frame);
 
     /* free the tmpblock */

     av_freep(&s->tmpblock);

 
     return 0;
 }
 

 static av_cold int flashsv_decode_init(AVCodecContext *avctx)

 {

     FlashSVContext *s = avctx->priv_data;

     int zret; // Zlib return code
 

     s->avctx          = avctx;

     s->zstream.zalloc = Z_NULL;

     s->zstream.zfree  = Z_NULL;

     s->zstream.opaque = Z_NULL;

     zret = inflateInit(&s->zstream);

     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
         return 1;
     }

     avctx->pix_fmt = AV_PIX_FMT_BGR24;

 
     s->frame = av_frame_alloc();
     if (!s->frame) {
         flashsv_decode_end(avctx);
         return AVERROR(ENOMEM);
     }

 
     return 0;
 }
 

 static int flashsv2_prime(FlashSVContext *s, uint8_t *src, int size)

 {
     z_stream zs;

     int zret; // Zlib return code

     if (!src)
         return AVERROR_INVALIDDATA;
 

     zs.zalloc = NULL;
     zs.zfree  = NULL;
     zs.opaque = NULL;
 
     s->zstream.next_in   = src;
     s->zstream.avail_in  = size;
     s->zstream.next_out  = s->tmpblock;
     s->zstream.avail_out = s->block_size * 3;
     inflate(&s->zstream, Z_SYNC_FLUSH);
 

     if (deflateInit(&zs, 0) != Z_OK)
         return -1;

     zs.next_in   = s->tmpblock;
     zs.avail_in  = s->block_size * 3 - s->zstream.avail_out;
     zs.next_out  = s->deflate_block;
     zs.avail_out = s->deflate_block_size;
     deflate(&zs, Z_SYNC_FLUSH);
     deflateEnd(&zs);
 

     if ((zret = inflateReset(&s->zstream)) != Z_OK) {
         av_log(s->avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
         return AVERROR_UNKNOWN;
     }

 
     s->zstream.next_in   = s->deflate_block;
     s->zstream.avail_in  = s->deflate_block_size - zs.avail_out;
     s->zstream.next_out  = s->tmpblock;
     s->zstream.avail_out = s->block_size * 3;
     inflate(&s->zstream, Z_SYNC_FLUSH);

 
     return 0;

 }
 

 static int flashsv_decode_block(AVCodecContext *avctx, AVPacket *avpkt,
                                 GetBitContext *gb, int block_size,

                                 int width, int height, int x_pos, int y_pos,
                                 int blk_idx)

 {
     struct FlashSVContext *s = avctx->priv_data;
     uint8_t *line = s->tmpblock;
     int k;
     int ret = inflateReset(&s->zstream);
     if (ret != Z_OK) {

         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
         return AVERROR_UNKNOWN;

     }

     if (s->zlibprime_curr || s->zlibprime_prev) {

         ret = flashsv2_prime(s,
                              s->blocks[blk_idx].pos,
                              s->blocks[blk_idx].size);

         if (ret < 0)
             return ret;

     }

     s->zstream.next_in   = avpkt->data + get_bits_count(gb) / 8;
     s->zstream.avail_in  = block_size;
     s->zstream.next_out  = s->tmpblock;
     s->zstream.avail_out = s->block_size * 3;
     ret = inflate(&s->zstream, Z_FINISH);
     if (ret == Z_DATA_ERROR) {
         av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
         inflateSync(&s->zstream);
         ret = inflate(&s->zstream, Z_FINISH);
     }
 
     if (ret != Z_OK && ret != Z_STREAM_END) {
         //return -1;
     }

 
     if (s->is_keyframe) {

         s->blocks[blk_idx].pos  = s->keyframedata + (get_bits_count(gb) / 8);
         s->blocks[blk_idx].size = block_size;

     }

 
     y_pos += s->diff_start;
 

     if (!s->color_depth) {
         /* Flash Screen Video stores the image upside down, so copy
          * lines to destination in reverse order. */
         for (k = 1; k <= s->diff_height; k++) {

             memcpy(s->frame->data[0] + x_pos * 3 +
                    (s->image_height - y_pos - k) * s->frame->linesize[0],

                    line, width * 3);
             /* advance source pointer to next line */
             line += width * 3;
         }
     } else {
         /* hybrid 15-bit/palette mode */

         ret = decode_hybrid(s->tmpblock, s->zstream.next_out,
                       s->frame->data[0],

                       s->image_height - (y_pos + 1 + s->diff_height),

                       x_pos, s->diff_height, width,

                       s->frame->linesize[0], s->pal);

         if (ret < 0) {
             av_log(avctx, AV_LOG_ERROR, "decode_hybrid failed\n");
             return ret;
         }

     }
     skip_bits_long(gb, 8 * block_size); /* skip the consumed bits */
     return 0;
 }
 

 static int calc_deflate_block_size(int tmpblock_size)
 {
     z_stream zstream;
     int size;
 
     zstream.zalloc = Z_NULL;
     zstream.zfree  = Z_NULL;
     zstream.opaque = Z_NULL;
     if (deflateInit(&zstream, 0) != Z_OK)
         return -1;
     size = deflateBound(&zstream, tmpblock_size);
     deflateEnd(&zstream);
 
     return size;
 }

 static int flashsv_decode_frame(AVCodecContext *avctx, void *data,

                                 int *got_frame, AVPacket *avpkt)

 {

     int buf_size = avpkt->size;
     FlashSVContext *s = avctx->priv_data;

     int h_blocks, v_blocks, h_part, v_part, i, j, ret;

     GetBitContext gb;

     int last_blockwidth = s->block_width;
     int last_blockheight= s->block_height;

 
     /* no supplementary picture */
     if (buf_size == 0)
         return 0;

     if (buf_size < 4)
         return -1;

     if ((ret = init_get_bits8(&gb, avpkt->data, buf_size)) < 0)

         return ret;

 
     /* start to parse the bitstream */

     s->block_width  = 16 * (get_bits(&gb, 4) + 1);
     s->image_width  = get_bits(&gb, 12);
     s->block_height = 16 * (get_bits(&gb, 4) + 1);
     s->image_height = get_bits(&gb, 12);

     if (   last_blockwidth != s->block_width
         || last_blockheight!= s->block_height)
         av_freep(&s->blocks);
 

     if (s->ver == 2) {
         skip_bits(&gb, 6);
         if (get_bits1(&gb)) {

             avpriv_request_sample(avctx, "iframe");

             return AVERROR_PATCHWELCOME;
         }
         if (get_bits1(&gb)) {

             avpriv_request_sample(avctx, "Custom palette");

             return AVERROR_PATCHWELCOME;
         }
     }
 

     /* calculate number of blocks and size of border (partial) blocks */

     h_blocks = s->image_width  / s->block_width;
     h_part   = s->image_width  % s->block_width;

     v_blocks = s->image_height / s->block_height;

     v_part   = s->image_height % s->block_height;

 
     /* the block size could change between frames, make sure the buffer
      * is large enough, if not, get a larger one */

     if (s->block_size < s->block_width * s->block_height) {

         int tmpblock_size = 3 * s->block_width * s->block_height, err;

         if ((err = av_reallocp(&s->tmpblock, tmpblock_size)) < 0) {
             s->block_size = 0;

             av_log(avctx, AV_LOG_ERROR,
                    "Cannot allocate decompression buffer.\n");

             return err;

         }

         if (s->ver == 2) {
             s->deflate_block_size = calc_deflate_block_size(tmpblock_size);
             if (s->deflate_block_size <= 0) {

                 av_log(avctx, AV_LOG_ERROR,
                        "Cannot determine deflate buffer size.\n");

                 return -1;
             }

             if ((err = av_reallocp(&s->deflate_block, s->deflate_block_size)) < 0) {
                 s->block_size = 0;
                 av_log(avctx, AV_LOG_ERROR, "Cannot allocate deflate buffer.\n");
                 return err;

             }
         }

     }

     s->block_size = s->block_width * s->block_height;

     /* initialize the image size once */

     if (avctx->width == 0 && avctx->height == 0) {

         if ((ret = ff_set_dimensions(avctx, s->image_width, s->image_height)) < 0)
             return ret;

     }
 
     /* check for changes of image width and image height */

     if (avctx->width != s->image_width || avctx->height != s->image_height) {

         av_log(avctx, AV_LOG_ERROR,

                "Frame width or height differs from first frame!\n");

         av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d  vs  ch = %d, cv = %d\n",
                avctx->height, avctx->width, s->image_height, s->image_width);

         return AVERROR_INVALIDDATA;

     }
 

     /* we care for keyframes only in Screen Video v2 */
     s->is_keyframe = (avpkt->flags & AV_PKT_FLAG_KEY) && (s->ver == 2);
     if (s->is_keyframe) {

         int err;
         if ((err = av_reallocp(&s->keyframedata, avpkt->size)) < 0)
             return err;

         memcpy(s->keyframedata, avpkt->data, avpkt->size);
     }

     if(s->ver == 2 && !s->blocks)

         s->blocks = av_mallocz((v_blocks + !!v_part) * (h_blocks + !!h_part) *
                                sizeof(s->blocks[0]));

     ff_dlog(avctx, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",

             s->image_width, s->image_height, s->block_width, s->block_height,
             h_blocks, v_blocks, h_part, v_part);

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

         return ret;

 
     /* loop over all block columns */

     for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {

         int y_pos  = j * s->block_height; // vertical position in frame
         int cur_blk_height = (j < v_blocks) ? s->block_height : v_part;

 
         /* loop over all block rows */

         for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {

             int x_pos = i * s->block_width; // horizontal position in frame
             int cur_blk_width = (i < h_blocks) ? s->block_width : h_part;

             int has_diff = 0;

 
             /* get the size of the compressed zlib chunk */
             int size = get_bits(&gb, 16);

 
             s->color_depth    = 0;
             s->zlibprime_curr = 0;
             s->zlibprime_prev = 0;
             s->diff_start     = 0;
             s->diff_height    = cur_blk_height;
 

             if (8 * size > get_bits_left(&gb)) {

                 av_frame_unref(s->frame);

                 return AVERROR_INVALIDDATA;

             }

             if (s->ver == 2 && size) {
                 skip_bits(&gb, 3);
                 s->color_depth    = get_bits(&gb, 2);
                 has_diff          = get_bits1(&gb);
                 s->zlibprime_curr = get_bits1(&gb);
                 s->zlibprime_prev = get_bits1(&gb);
 
                 if (s->color_depth != 0 && s->color_depth != 2) {
                     av_log(avctx, AV_LOG_ERROR,

                            "%dx%d invalid color depth %d\n",
                            i, j, s->color_depth);

                     return AVERROR_INVALIDDATA;

                 }
 
                 if (has_diff) {

                     if (size < 3) {
                         av_log(avctx, AV_LOG_ERROR, "size too small for diff\n");
                         return AVERROR_INVALIDDATA;
                     }

                     if (!s->keyframe) {
                         av_log(avctx, AV_LOG_ERROR,

                                "Inter frame without keyframe\n");

                         return AVERROR_INVALIDDATA;
                     }

                     s->diff_start  = get_bits(&gb, 8);
                     s->diff_height = get_bits(&gb, 8);

                     if (s->diff_start + s->diff_height > cur_blk_height) {

                         av_log(avctx, AV_LOG_ERROR,
                                "Block parameters invalid: %d + %d > %d\n",
                                s->diff_start, s->diff_height, cur_blk_height);

                         return AVERROR_INVALIDDATA;
                     }

                     av_log(avctx, AV_LOG_DEBUG,
                            "%dx%d diff start %d height %d\n",
                            i, j, s->diff_start, s->diff_height);
                     size -= 2;
                 }
 
                 if (s->zlibprime_prev)
                     av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_prev\n", i, j);
 
                 if (s->zlibprime_curr) {
                     int col = get_bits(&gb, 8);
                     int row = get_bits(&gb, 8);

                     av_log(avctx, AV_LOG_DEBUG, "%dx%d zlibprime_curr %dx%d\n",
                            i, j, col, row);

                     if (size < 3) {
                         av_log(avctx, AV_LOG_ERROR, "size too small for zlibprime_curr\n");
                         return AVERROR_INVALIDDATA;
                     }

                     size -= 2;

                     avpriv_request_sample(avctx, "zlibprime_curr");

                     return AVERROR_PATCHWELCOME;
                 }

                 if (!s->blocks && (s->zlibprime_curr || s->zlibprime_prev)) {

                     av_log(avctx, AV_LOG_ERROR,
                            "no data available for zlib priming\n");

                     return AVERROR_INVALIDDATA;
                 }

                 size--; // account for flags byte
             }
 
             if (has_diff) {
                 int k;

                 int off = (s->image_height - y_pos - 1) * s->frame->linesize[0];

                 for (k = 0; k < cur_blk_height; k++) {

                     int x = off - k * s->frame->linesize[0] + x_pos * 3;
                     memcpy(s->frame->data[0] + x, s->keyframe + x,

                            cur_blk_width * 3);

                 }

             }
 

             /* skip unchanged blocks, which have size 0 */
             if (size) {

                 if (flashsv_decode_block(avctx, avpkt, &gb, size,
                                          cur_blk_width, cur_blk_height,

                                          x_pos, y_pos,
                                          i + j * (h_blocks + !!h_part)))

                     av_log(avctx, AV_LOG_ERROR,

                            "error in decompression of block %dx%d\n", i, j);

             }
         }
     }

     if (s->is_keyframe && s->ver == 2) {
         if (!s->keyframe) {

             s->keyframe = av_malloc(s->frame->linesize[0] * avctx->height);

             if (!s->keyframe) {
                 av_log(avctx, AV_LOG_ERROR, "Cannot allocate image data\n");
                 return AVERROR(ENOMEM);
             }
         }

         memcpy(s->keyframe, s->frame->data[0],
                s->frame->linesize[0] * avctx->height);

     }

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

         return ret;
 

     *got_frame = 1;

     if ((get_bits_count(&gb) / 8) != buf_size)

         av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",

                buf_size, (get_bits_count(&gb) / 8));

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

 #if CONFIG_FLASHSV_DECODER

 AVCodec ff_flashsv_decoder = {

     .name           = "flashsv",

     .long_name      = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_FLASHSV,

     .priv_data_size = sizeof(FlashSVContext),
     .init           = flashsv_decode_init,
     .close          = flashsv_decode_end,
     .decode         = flashsv_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },

 };

 #endif /* CONFIG_FLASHSV_DECODER */
 
 #if CONFIG_FLASHSV2_DECODER
 static const uint32_t ff_flashsv2_default_palette[128] = {
     0x000000, 0x333333, 0x666666, 0x999999, 0xCCCCCC, 0xFFFFFF,
     0x330000, 0x660000, 0x990000, 0xCC0000, 0xFF0000, 0x003300,
     0x006600, 0x009900, 0x00CC00, 0x00FF00, 0x000033, 0x000066,
     0x000099, 0x0000CC, 0x0000FF, 0x333300, 0x666600, 0x999900,
     0xCCCC00, 0xFFFF00, 0x003333, 0x006666, 0x009999, 0x00CCCC,
     0x00FFFF, 0x330033, 0x660066, 0x990099, 0xCC00CC, 0xFF00FF,
     0xFFFF33, 0xFFFF66, 0xFFFF99, 0xFFFFCC, 0xFF33FF, 0xFF66FF,
     0xFF99FF, 0xFFCCFF, 0x33FFFF, 0x66FFFF, 0x99FFFF, 0xCCFFFF,
     0xCCCC33, 0xCCCC66, 0xCCCC99, 0xCCCCFF, 0xCC33CC, 0xCC66CC,
     0xCC99CC, 0xCCFFCC, 0x33CCCC, 0x66CCCC, 0x99CCCC, 0xFFCCCC,
     0x999933, 0x999966, 0x9999CC, 0x9999FF, 0x993399, 0x996699,
     0x99CC99, 0x99FF99, 0x339999, 0x669999, 0xCC9999, 0xFF9999,
     0x666633, 0x666699, 0x6666CC, 0x6666FF, 0x663366, 0x669966,
     0x66CC66, 0x66FF66, 0x336666, 0x996666, 0xCC6666, 0xFF6666,
     0x333366, 0x333399, 0x3333CC, 0x3333FF, 0x336633, 0x339933,
     0x33CC33, 0x33FF33, 0x663333, 0x993333, 0xCC3333, 0xFF3333,
     0x003366, 0x336600, 0x660033, 0x006633, 0x330066, 0x663300,
     0x336699, 0x669933, 0x993366, 0x339966, 0x663399, 0x996633,
     0x6699CC, 0x99CC66, 0xCC6699, 0x66CC99, 0x9966CC, 0xCC9966,
     0x99CCFF, 0xCCFF99, 0xFF99CC, 0x99FFCC, 0xCC99FF, 0xFFCC99,
     0x111111, 0x222222, 0x444444, 0x555555, 0xAAAAAA, 0xBBBBBB,
     0xDDDDDD, 0xEEEEEE
 };
 
 static av_cold int flashsv2_decode_init(AVCodecContext *avctx)
 {
     FlashSVContext *s = avctx->priv_data;
     flashsv_decode_init(avctx);
     s->pal = ff_flashsv2_default_palette;
     s->ver = 2;
 
     return 0;
 }
 
 static av_cold int flashsv2_decode_end(AVCodecContext *avctx)
 {
     FlashSVContext *s = avctx->priv_data;
 
     av_freep(&s->keyframedata);
     av_freep(&s->blocks);
     av_freep(&s->keyframe);
     av_freep(&s->deflate_block);
     flashsv_decode_end(avctx);
 
     return 0;
 }
 
 AVCodec ff_flashsv2_decoder = {
     .name           = "flashsv2",

     .long_name      = NULL_IF_CONFIG_SMALL("Flash Screen Video v2"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_FLASHSV2,

     .priv_data_size = sizeof(FlashSVContext),
     .init           = flashsv2_decode_init,
     .close          = flashsv2_decode_end,
     .decode         = flashsv_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },

 };
 #endif /* CONFIG_FLASHSV2_DECODER */