/*
  * innoHeim/Rsupport Screen Capture Codec
  * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
  *

  * 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
  * innoHeim/Rsupport Screen Capture Codec decoder
  *
  * Fourcc: ISCC, RSCC
  *
  * Lossless codec, data stored in tiles, with optional deflate compression.
  *
  * Header contains the number of tiles in a frame with the tile coordinates,
  * and it can be deflated or not. Similarly, pixel data comes after the header
  * and a variable size value, and it can be deflated or just raw.
  *

  * Supports: PAL8, BGRA, BGR24, RGB555

  */
 
 #include <stdint.h>
 #include <string.h>
 #include <zlib.h>
 
 #include "libavutil/imgutils.h"
 #include "libavutil/internal.h"
 
 #include "avcodec.h"
 #include "bytestream.h"
 #include "internal.h"
 
 #define TILE_SIZE 8
 
 typedef struct Tile {
     int x, y;
     int w, h;
 } Tile;
 
 typedef struct RsccContext {
     GetByteContext gbc;
     AVFrame *reference;
     Tile *tiles;
     unsigned int tiles_size;

     int component_size;

     uint8_t palette[AVPALETTE_SIZE];

 
     /* zlib interaction */
     uint8_t *inflated_buf;
     uLongf inflated_size;
 } RsccContext;
 
 static av_cold int rscc_init(AVCodecContext *avctx)
 {
     RsccContext *ctx = avctx->priv_data;
 
     /* These needs to be set to estimate uncompressed buffer */
     int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
                avctx->width, avctx->height);
         return ret;
     }
 
     /* Allocate reference frame */
     ctx->reference = av_frame_alloc();
     if (!ctx->reference)
         return AVERROR(ENOMEM);
 

     /* Get pixel format and the size of the pixel */
     if (avctx->codec_tag == MKTAG('I', 'S', 'C', 'C')) {

         avctx->pix_fmt = AV_PIX_FMT_BGRA;

         ctx->component_size = 4;
     } else if (avctx->codec_tag == MKTAG('R', 'S', 'C', 'C')) {
         ctx->component_size = avctx->bits_per_coded_sample / 8;
         switch (avctx->bits_per_coded_sample) {
         case 8:

             avctx->pix_fmt = AV_PIX_FMT_PAL8;

             break;

         case 16:
             avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
             break;
         case 24:
             avctx->pix_fmt = AV_PIX_FMT_BGR24;
             break;
         case 32:

             avctx->pix_fmt = AV_PIX_FMT_BGR0;

             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "Invalid bits per pixel value (%d)\n",
                    avctx->bits_per_coded_sample);
             return AVERROR_INVALIDDATA;
         }

     } else {
         avctx->pix_fmt = AV_PIX_FMT_BGR0;

         ctx->component_size = 4;
         av_log(avctx, AV_LOG_WARNING, "Invalid codec tag\n");

     }

 
     /* Store the value to check for keyframes */

     ctx->inflated_size = avctx->width * avctx->height * ctx->component_size;

 
     /* Allocate maximum size possible, a full frame */
     ctx->inflated_buf = av_malloc(ctx->inflated_size);
     if (!ctx->inflated_buf)
         return AVERROR(ENOMEM);
 
     return 0;
 }
 
 static av_cold int rscc_close(AVCodecContext *avctx)
 {
     RsccContext *ctx = avctx->priv_data;
 
     av_freep(&ctx->tiles);
     av_freep(&ctx->inflated_buf);
     av_frame_free(&ctx->reference);
 
     return 0;
 }
 
 static int rscc_decode_frame(AVCodecContext *avctx, void *data,
                                      int *got_frame, AVPacket *avpkt)
 {
     RsccContext *ctx = avctx->priv_data;
     GetByteContext *gbc = &ctx->gbc;
     GetByteContext tiles_gbc;
     AVFrame *frame = data;
     const uint8_t *pixels, *raw;
     uint8_t *inflated_tiles = NULL;
     int tiles_nb, packed_size, pixel_size = 0;
     int i, ret = 0;
 
     bytestream2_init(gbc, avpkt->data, avpkt->size);
 
     /* Size check */
     if (bytestream2_get_bytes_left(gbc) < 12) {
         av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
         return AVERROR_INVALIDDATA;
     }
 
     /* Read number of tiles, and allocate the array */
     tiles_nb = bytestream2_get_le16(gbc);
     av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
                    tiles_nb * sizeof(*ctx->tiles));
     if (!ctx->tiles) {
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
 
     /* When there are more than 5 tiles, they are packed together with
      * a size header. When that size does not match the number of tiles
      * times the tile size, it means it needs to be inflated as well */
     if (tiles_nb > 5) {
         uLongf packed_tiles_size;
 
         if (tiles_nb < 32)
             packed_tiles_size = bytestream2_get_byte(gbc);
         else
             packed_tiles_size = bytestream2_get_le16(gbc);
 
         ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
 
         /* If necessary, uncompress tiles, and hijack the bytestream reader */
         if (packed_tiles_size != tiles_nb * TILE_SIZE) {
             uLongf length = tiles_nb * TILE_SIZE;
             inflated_tiles = av_malloc(length);
             if (!inflated_tiles) {
                 ret = AVERROR(ENOMEM);
                 goto end;
             }
 
             ret = uncompress(inflated_tiles, &length,
                              gbc->buffer, packed_tiles_size);
             if (ret) {
                 av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
                 ret = AVERROR_UNKNOWN;
                 goto end;
             }
 
             /* Skip the compressed tile section in the main byte reader,
              * and point it to read the newly uncompressed data */
             bytestream2_skip(gbc, packed_tiles_size);
             bytestream2_init(&tiles_gbc, inflated_tiles, length);
             gbc = &tiles_gbc;
         }
     }
 
     /* Fill in array of tiles, keeping track of how many pixels are updated */
     for (i = 0; i < tiles_nb; i++) {
         ctx->tiles[i].x = bytestream2_get_le16(gbc);
         ctx->tiles[i].w = bytestream2_get_le16(gbc);
         ctx->tiles[i].y = bytestream2_get_le16(gbc);
         ctx->tiles[i].h = bytestream2_get_le16(gbc);
 

         if (pixel_size + ctx->tiles[i].w * (int64_t)ctx->tiles[i].h * ctx->component_size > INT_MAX) {
             av_log(avctx, AV_LOG_ERROR, "Invalid tile dimensions\n");
             ret = AVERROR_INVALIDDATA;
             goto end;
         }
 

         pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * ctx->component_size;

 
         ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
                 ctx->tiles[i].x, ctx->tiles[i].y,
                 ctx->tiles[i].w, ctx->tiles[i].h);
 
         if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
             av_log(avctx, AV_LOG_ERROR,
                    "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
                    ctx->tiles[i].x, ctx->tiles[i].y,
                    ctx->tiles[i].w, ctx->tiles[i].h);
             ret = AVERROR_INVALIDDATA;
             goto end;
         } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
                    ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
             av_log(avctx, AV_LOG_ERROR,
                    "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
                    ctx->tiles[i].x, ctx->tiles[i].y,
                    ctx->tiles[i].w, ctx->tiles[i].h);
             ret = AVERROR_INVALIDDATA;
             goto end;
         }
     }
 
     /* Reset the reader in case it had been modified before */
     gbc = &ctx->gbc;
 
     /* Extract how much pixel data the tiles contain */
     if (pixel_size < 0x100)
         packed_size = bytestream2_get_byte(gbc);
     else if (pixel_size < 0x10000)
         packed_size = bytestream2_get_le16(gbc);
     else if (pixel_size < 0x1000000)
         packed_size = bytestream2_get_le24(gbc);
     else
         packed_size = bytestream2_get_le32(gbc);
 
     ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
 

     if (packed_size < 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid tile size %d\n", packed_size);
         ret = AVERROR_INVALIDDATA;
         goto end;
     }
 

     /* Get pixels buffer, it may be deflated or just raw */
     if (pixel_size == packed_size) {

         if (bytestream2_get_bytes_left(gbc) < pixel_size) {
             av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", pixel_size);
             ret = AVERROR_INVALIDDATA;
             goto end;
         }

         pixels = gbc->buffer;
     } else {
         uLongf len = ctx->inflated_size;

         if (bytestream2_get_bytes_left(gbc) < packed_size) {
             av_log(avctx, AV_LOG_ERROR, "Insufficient input for %d\n", packed_size);
             ret = AVERROR_INVALIDDATA;
             goto end;
         }

         ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
         if (ret) {
             av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
             ret = AVERROR_UNKNOWN;
             goto end;
         }
         pixels = ctx->inflated_buf;
     }
 
     /* Allocate when needed */
     ret = ff_reget_buffer(avctx, ctx->reference);
     if (ret < 0)
         goto end;
 
     /* Pointer to actual pixels, will be updated when data is consumed */
     raw = pixels;
     for (i = 0; i < tiles_nb; i++) {
         uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
                        (avctx->height - ctx->tiles[i].y - 1) +

                        ctx->tiles[i].x * ctx->component_size;

         av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],

                             raw, ctx->tiles[i].w * ctx->component_size,
                             ctx->tiles[i].w * ctx->component_size,
                             ctx->tiles[i].h);
         raw += ctx->tiles[i].w * ctx->component_size * ctx->tiles[i].h;

     }
 
     /* Frame is ready to be output */
     ret = av_frame_ref(frame, ctx->reference);
     if (ret < 0)
         goto end;
 
     /* Keyframe when the number of pixels updated matches the whole surface */
     if (pixel_size == ctx->inflated_size) {
         frame->pict_type = AV_PICTURE_TYPE_I;
         frame->key_frame = 1;
     } else {
         frame->pict_type = AV_PICTURE_TYPE_P;
     }

 
     /* Palette handling */

     if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {

         int size;

         const uint8_t *palette = av_packet_get_side_data(avpkt,
                                                          AV_PKT_DATA_PALETTE,

                                                          &size);
         if (palette && size == AVPALETTE_SIZE) {

             frame->palette_has_changed = 1;

             memcpy(ctx->palette, palette, AVPALETTE_SIZE);

         } else if (palette) {

             av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);

         }

         memcpy (frame->data[1], ctx->palette, AVPALETTE_SIZE);

     }

     *got_frame = 1;
 

     ret = avpkt->size;

 end:
     av_free(inflated_tiles);
     return ret;
 }
 
 AVCodec ff_rscc_decoder = {
     .name           = "rscc",
     .long_name      = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_RSCC,
     .init           = rscc_init,
     .decode         = rscc_decode_frame,
     .close          = rscc_close,
     .priv_data_size = sizeof(RsccContext),
     .capabilities   = AV_CODEC_CAP_DR1,
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
                       FF_CODEC_CAP_INIT_CLEANUP,
 };