/*
  * Quicktime Graphics (SMC) Video 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 libavcodec/smc.c

  * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
  * For more information about the SMC format, visit:
  *   http://www.pcisys.net/~melanson/codecs/
  *
  * The SMC decoder outputs PAL8 colorspace data.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 

 #include "libavutil/intreadwrite.h"

 #include "avcodec.h"
 
 #define CPAIR 2
 #define CQUAD 4
 #define COCTET 8
 
 #define COLORS_PER_TABLE 256
 
 typedef struct SmcContext {
 
     AVCodecContext *avctx;
     AVFrame frame;
 

     const unsigned char *buf;

     int size;
 
     /* SMC color tables */
     unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
     unsigned char color_quads[COLORS_PER_TABLE * CQUAD];
     unsigned char color_octets[COLORS_PER_TABLE * COCTET];
 
 } SmcContext;
 
 #define GET_BLOCK_COUNT() \
   (opcode & 0x10) ? (1 + s->buf[stream_ptr++]) : 1 + (opcode & 0x0F);
 
 #define ADVANCE_BLOCK() \
 { \
     pixel_ptr += 4; \
     if (pixel_ptr >= width) \
     { \
         pixel_ptr = 0; \
         row_ptr += stride * 4; \
     } \
     total_blocks--; \
     if (total_blocks < 0) \
     { \

         av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \

         return; \
     } \
 }
 
 static void smc_decode_stream(SmcContext *s)
 {
     int width = s->avctx->width;
     int height = s->avctx->height;
     int stride = s->frame.linesize[0];
     int i;
     int stream_ptr = 0;
     int chunk_size;
     unsigned char opcode;
     int n_blocks;
     unsigned int color_flags;
     unsigned int color_flags_a;
     unsigned int color_flags_b;
     unsigned int flag_mask;
 
     unsigned char *pixels = s->frame.data[0];
 
     int image_size = height * s->frame.linesize[0];
     int row_ptr = 0;
     int pixel_ptr = 0;
     int pixel_x, pixel_y;
     int row_inc = stride - 4;
     int block_ptr;
     int prev_block_ptr;
     int prev_block_ptr1, prev_block_ptr2;
     int prev_block_flag;
     int total_blocks;
     int color_table_index;  /* indexes to color pair, quad, or octet tables */
     int pixel;
 
     int color_pair_index = 0;
     int color_quad_index = 0;
     int color_octet_index = 0;
 
     /* make the palette available */
     memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
     if (s->avctx->palctrl->palette_changed) {
         s->frame.palette_has_changed = 1;
         s->avctx->palctrl->palette_changed = 0;
     }
 

     chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;

     stream_ptr += 4;
     if (chunk_size != s->size)

         av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",

             chunk_size, s->size);
 
     chunk_size = s->size;

     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);

 
     /* traverse through the blocks */
     while (total_blocks) {
         /* sanity checks */
         /* make sure stream ptr hasn't gone out of bounds */
         if (stream_ptr > chunk_size) {

             av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (stream ptr = %d, chunk size = %d)\n",

                 stream_ptr, chunk_size);
             return;
         }
         /* make sure the row pointer hasn't gone wild */
         if (row_ptr >= image_size) {

             av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",

                 row_ptr, image_size);
             return;
         }
 
         opcode = s->buf[stream_ptr++];
         switch (opcode & 0xF0) {
         /* skip n blocks */
         case 0x00:
         case 0x10:
             n_blocks = GET_BLOCK_COUNT();
             while (n_blocks--) {
                 ADVANCE_BLOCK();
             }
             break;
 
         /* repeat last block n times */
         case 0x20:
         case 0x30:
             n_blocks = GET_BLOCK_COUNT();
 
             /* sanity check */
             if ((row_ptr == 0) && (pixel_ptr == 0)) {

                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",

                     opcode & 0xF0);
                 break;
             }
 
             /* figure out where the previous block started */
             if (pixel_ptr == 0)

                 prev_block_ptr1 =

                     (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
             else
                 prev_block_ptr1 = row_ptr + pixel_ptr - 4;
 
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 prev_block_ptr = prev_block_ptr1;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = pixels[prev_block_ptr++];
                     }
                     block_ptr += row_inc;
                     prev_block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* repeat previous pair of blocks n times */
         case 0x40:
         case 0x50:
             n_blocks = GET_BLOCK_COUNT();
             n_blocks *= 2;
 
             /* sanity check */
             if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {

                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",

                     opcode & 0xF0);
                 break;
             }
 
             /* figure out where the previous 2 blocks started */
             if (pixel_ptr == 0)

                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +

                     s->avctx->width - 4 * 2;
             else if (pixel_ptr == 4)
                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
             else
                 prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
 
             if (pixel_ptr == 0)
                 prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
             else
                 prev_block_ptr2 = row_ptr + pixel_ptr - 4;
 
             prev_block_flag = 0;
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 if (prev_block_flag)
                     prev_block_ptr = prev_block_ptr2;
                 else
                     prev_block_ptr = prev_block_ptr1;
                 prev_block_flag = !prev_block_flag;
 
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = pixels[prev_block_ptr++];
                     }
                     block_ptr += row_inc;
                     prev_block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 1-color block encoding */
         case 0x60:
         case 0x70:
             n_blocks = GET_BLOCK_COUNT();
             pixel = s->buf[stream_ptr++];
 
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = pixel;
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 2-color block encoding */
         case 0x80:
         case 0x90:
             n_blocks = (opcode & 0x0F) + 1;
 
             /* figure out which color pair to use to paint the 2-color block */
             if ((opcode & 0xF0) == 0x80) {
                 /* fetch the next 2 colors from bytestream and store in next
                  * available entry in the color pair table */
                 for (i = 0; i < CPAIR; i++) {
                     pixel = s->buf[stream_ptr++];
                     color_table_index = CPAIR * color_pair_index + i;
                     s->color_pairs[color_table_index] = pixel;
                 }
                 /* this is the base index to use for this block */
                 color_table_index = CPAIR * color_pair_index;
                 color_pair_index++;
                 /* wraparound */
                 if (color_pair_index == COLORS_PER_TABLE)
                     color_pair_index = 0;
             } else
                 color_table_index = CPAIR * s->buf[stream_ptr++];
 
             while (n_blocks--) {

                 color_flags = AV_RB16(&s->buf[stream_ptr]);

                 stream_ptr += 2;
                 flag_mask = 0x8000;
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         if (color_flags & flag_mask)
                             pixel = color_table_index + 1;
                         else
                             pixel = color_table_index;
                         flag_mask >>= 1;
                         pixels[block_ptr++] = s->color_pairs[pixel];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 4-color block encoding */
         case 0xA0:
         case 0xB0:
             n_blocks = (opcode & 0x0F) + 1;
 
             /* figure out which color quad to use to paint the 4-color block */
             if ((opcode & 0xF0) == 0xA0) {
                 /* fetch the next 4 colors from bytestream and store in next
                  * available entry in the color quad table */
                 for (i = 0; i < CQUAD; i++) {
                     pixel = s->buf[stream_ptr++];
                     color_table_index = CQUAD * color_quad_index + i;
                     s->color_quads[color_table_index] = pixel;
                 }
                 /* this is the base index to use for this block */
                 color_table_index = CQUAD * color_quad_index;
                 color_quad_index++;
                 /* wraparound */
                 if (color_quad_index == COLORS_PER_TABLE)
                     color_quad_index = 0;
             } else
                 color_table_index = CQUAD * s->buf[stream_ptr++];
 
             while (n_blocks--) {

                 color_flags = AV_RB32(&s->buf[stream_ptr]);

                 stream_ptr += 4;
                 /* flag mask actually acts as a bit shift count here */
                 flag_mask = 30;
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {

                         pixel = color_table_index +

                             ((color_flags >> flag_mask) & 0x03);
                         flag_mask -= 2;
                         pixels[block_ptr++] = s->color_quads[pixel];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 8-color block encoding */
         case 0xC0:
         case 0xD0:
             n_blocks = (opcode & 0x0F) + 1;
 
             /* figure out which color octet to use to paint the 8-color block */
             if ((opcode & 0xF0) == 0xC0) {
                 /* fetch the next 8 colors from bytestream and store in next
                  * available entry in the color octet table */
                 for (i = 0; i < COCTET; i++) {
                     pixel = s->buf[stream_ptr++];
                     color_table_index = COCTET * color_octet_index + i;
                     s->color_octets[color_table_index] = pixel;
                 }
                 /* this is the base index to use for this block */
                 color_table_index = COCTET * color_octet_index;
                 color_octet_index++;
                 /* wraparound */
                 if (color_octet_index == COLORS_PER_TABLE)
                     color_octet_index = 0;
             } else
                 color_table_index = COCTET * s->buf[stream_ptr++];
 
             while (n_blocks--) {
                 /*
                   For this input of 6 hex bytes:
                     01 23 45 67 89 AB
                   Mangle it to this output:
                     flags_a = xx012456, flags_b = xx89A37B
                 */
                 /* build the color flags */
                 color_flags_a = color_flags_b = 0;
                 color_flags_a =
                     (s->buf[stream_ptr + 0] << 16) |
                     ((s->buf[stream_ptr + 1] & 0xF0) << 8) |
                     ((s->buf[stream_ptr + 2] & 0xF0) << 4) |
                     ((s->buf[stream_ptr + 2] & 0x0F) << 4) |
                     ((s->buf[stream_ptr + 3] & 0xF0) >> 4);
                 color_flags_b =
                     (s->buf[stream_ptr + 4] << 16) |
                     ((s->buf[stream_ptr + 5] & 0xF0) << 8) |
                     ((s->buf[stream_ptr + 1] & 0x0F) << 8) |
                     ((s->buf[stream_ptr + 3] & 0x0F) << 4) |
                     (s->buf[stream_ptr + 5] & 0x0F);
                 stream_ptr += 6;
 
                 color_flags = color_flags_a;
                 /* flag mask actually acts as a bit shift count here */
                 flag_mask = 21;
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     /* reload flags at third row (iteration pixel_y == 2) */
                     if (pixel_y == 2) {
                         color_flags = color_flags_b;
                         flag_mask = 21;
                     }
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {

                         pixel = color_table_index +

                             ((color_flags >> flag_mask) & 0x07);
                         flag_mask -= 3;
                         pixels[block_ptr++] = s->color_octets[pixel];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         /* 16-color block encoding (every pixel is a different color) */
         case 0xE0:
             n_blocks = (opcode & 0x0F) + 1;
 
             while (n_blocks--) {
                 block_ptr = row_ptr + pixel_ptr;
                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
                         pixels[block_ptr++] = s->buf[stream_ptr++];
                     }
                     block_ptr += row_inc;
                 }
                 ADVANCE_BLOCK();
             }
             break;
 
         case 0xF0:

             av_log(s->avctx, AV_LOG_INFO, "0xF0 opcode seen in SMC chunk (contact the developers)\n");

             break;
         }
     }
 }
 

 static av_cold int smc_decode_init(AVCodecContext *avctx)

 {

     SmcContext *s = avctx->priv_data;

 
     s->avctx = avctx;
     avctx->pix_fmt = PIX_FMT_PAL8;
 

     s->frame.data[0] = NULL;

 
     return 0;
 }
 
 static int smc_decode_frame(AVCodecContext *avctx,
                              void *data, int *data_size,

                              const uint8_t *buf, int buf_size)

 {

     SmcContext *s = avctx->priv_data;

 
     s->buf = buf;
     s->size = buf_size;
 
     s->frame.reference = 1;

     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |

                             FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE;

     if (avctx->reget_buffer(avctx, &s->frame)) {

         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");

         return -1;
     }
 
     smc_decode_stream(s);
 
     *data_size = sizeof(AVFrame);
     *(AVFrame*)data = s->frame;
 
     /* always report that the buffer was completely consumed */
     return buf_size;
 }
 

 static av_cold int smc_decode_end(AVCodecContext *avctx)

 {

     SmcContext *s = avctx->priv_data;

     if (s->frame.data[0])
         avctx->release_buffer(avctx, &s->frame);

 
     return 0;
 }
 
 AVCodec smc_decoder = {
     "smc",
     CODEC_TYPE_VIDEO,
     CODEC_ID_SMC,
     sizeof(SmcContext),
     smc_decode_init,
     NULL,
     smc_decode_end,
     smc_decode_frame,
     CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"),

 };