yading@10: /*
yading@10:  * Quicktime Graphics (SMC) Video Decoder
yading@10:  * Copyright (C) 2003 the ffmpeg project
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
yading@10:  * For more information about the SMC format, visit:
yading@10:  *   http://www.pcisys.net/~melanson/codecs/
yading@10:  *
yading@10:  * The SMC decoder outputs PAL8 colorspace data.
yading@10:  */
yading@10: 
yading@10: #include <stdio.h>
yading@10: #include <stdlib.h>
yading@10: #include <string.h>
yading@10: 
yading@10: #include "libavutil/intreadwrite.h"
yading@10: #include "avcodec.h"
yading@10: #include "bytestream.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: #define CPAIR 2
yading@10: #define CQUAD 4
yading@10: #define COCTET 8
yading@10: 
yading@10: #define COLORS_PER_TABLE 256
yading@10: 
yading@10: typedef struct SmcContext {
yading@10: 
yading@10:     AVCodecContext *avctx;
yading@10:     AVFrame frame;
yading@10: 
yading@10:     GetByteContext gb;
yading@10: 
yading@10:     /* SMC color tables */
yading@10:     unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
yading@10:     unsigned char color_quads[COLORS_PER_TABLE * CQUAD];
yading@10:     unsigned char color_octets[COLORS_PER_TABLE * COCTET];
yading@10: 
yading@10:     uint32_t pal[256];
yading@10: } SmcContext;
yading@10: 
yading@10: #define GET_BLOCK_COUNT() \
yading@10:   (opcode & 0x10) ? (1 + bytestream2_get_byte(&s->gb)) : 1 + (opcode & 0x0F);
yading@10: 
yading@10: #define ADVANCE_BLOCK() \
yading@10: { \
yading@10:     pixel_ptr += 4; \
yading@10:     if (pixel_ptr >= width) \
yading@10:     { \
yading@10:         pixel_ptr = 0; \
yading@10:         row_ptr += stride * 4; \
yading@10:     } \
yading@10:     total_blocks--; \
yading@10:     if (total_blocks < 0) \
yading@10:     { \
yading@10:         av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \
yading@10:         return; \
yading@10:     } \
yading@10: }
yading@10: 
yading@10: static void smc_decode_stream(SmcContext *s)
yading@10: {
yading@10:     int width = s->avctx->width;
yading@10:     int height = s->avctx->height;
yading@10:     int stride = s->frame.linesize[0];
yading@10:     int i;
yading@10:     int chunk_size;
yading@10:     int buf_size = bytestream2_size(&s->gb);
yading@10:     unsigned char opcode;
yading@10:     int n_blocks;
yading@10:     unsigned int color_flags;
yading@10:     unsigned int color_flags_a;
yading@10:     unsigned int color_flags_b;
yading@10:     unsigned int flag_mask;
yading@10: 
yading@10:     unsigned char *pixels = s->frame.data[0];
yading@10: 
yading@10:     int image_size = height * s->frame.linesize[0];
yading@10:     int row_ptr = 0;
yading@10:     int pixel_ptr = 0;
yading@10:     int pixel_x, pixel_y;
yading@10:     int row_inc = stride - 4;
yading@10:     int block_ptr;
yading@10:     int prev_block_ptr;
yading@10:     int prev_block_ptr1, prev_block_ptr2;
yading@10:     int prev_block_flag;
yading@10:     int total_blocks;
yading@10:     int color_table_index;  /* indexes to color pair, quad, or octet tables */
yading@10:     int pixel;
yading@10: 
yading@10:     int color_pair_index = 0;
yading@10:     int color_quad_index = 0;
yading@10:     int color_octet_index = 0;
yading@10: 
yading@10:     /* make the palette available */
yading@10:     memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
yading@10: 
yading@10:     bytestream2_skip(&s->gb, 1);
yading@10:     chunk_size = bytestream2_get_be24(&s->gb);
yading@10:     if (chunk_size != buf_size)
yading@10:         av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
yading@10:             chunk_size, buf_size);
yading@10: 
yading@10:     chunk_size = buf_size;
yading@10:     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
yading@10: 
yading@10:     /* traverse through the blocks */
yading@10:     while (total_blocks) {
yading@10:         /* sanity checks */
yading@10:         /* make sure the row pointer hasn't gone wild */
yading@10:         if (row_ptr >= image_size) {
yading@10:             av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",
yading@10:                 row_ptr, image_size);
yading@10:             return;
yading@10:         }
yading@10: 
yading@10:         opcode = bytestream2_get_byte(&s->gb);
yading@10:         switch (opcode & 0xF0) {
yading@10:         /* skip n blocks */
yading@10:         case 0x00:
yading@10:         case 0x10:
yading@10:             n_blocks = GET_BLOCK_COUNT();
yading@10:             while (n_blocks--) {
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* repeat last block n times */
yading@10:         case 0x20:
yading@10:         case 0x30:
yading@10:             n_blocks = GET_BLOCK_COUNT();
yading@10: 
yading@10:             /* sanity check */
yading@10:             if ((row_ptr == 0) && (pixel_ptr == 0)) {
yading@10:                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",
yading@10:                     opcode & 0xF0);
yading@10:                 return;
yading@10:             }
yading@10: 
yading@10:             /* figure out where the previous block started */
yading@10:             if (pixel_ptr == 0)
yading@10:                 prev_block_ptr1 =
yading@10:                     (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
yading@10:             else
yading@10:                 prev_block_ptr1 = row_ptr + pixel_ptr - 4;
yading@10: 
yading@10:             while (n_blocks--) {
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 prev_block_ptr = prev_block_ptr1;
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         pixels[block_ptr++] = pixels[prev_block_ptr++];
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                     prev_block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* repeat previous pair of blocks n times */
yading@10:         case 0x40:
yading@10:         case 0x50:
yading@10:             n_blocks = GET_BLOCK_COUNT();
yading@10:             n_blocks *= 2;
yading@10: 
yading@10:             /* sanity check */
yading@10:             if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {
yading@10:                 av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
yading@10:                     opcode & 0xF0);
yading@10:                 return;
yading@10:             }
yading@10: 
yading@10:             /* figure out where the previous 2 blocks started */
yading@10:             if (pixel_ptr == 0)
yading@10:                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +
yading@10:                     s->avctx->width - 4 * 2;
yading@10:             else if (pixel_ptr == 4)
yading@10:                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
yading@10:             else
yading@10:                 prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
yading@10: 
yading@10:             if (pixel_ptr == 0)
yading@10:                 prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
yading@10:             else
yading@10:                 prev_block_ptr2 = row_ptr + pixel_ptr - 4;
yading@10: 
yading@10:             prev_block_flag = 0;
yading@10:             while (n_blocks--) {
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 if (prev_block_flag)
yading@10:                     prev_block_ptr = prev_block_ptr2;
yading@10:                 else
yading@10:                     prev_block_ptr = prev_block_ptr1;
yading@10:                 prev_block_flag = !prev_block_flag;
yading@10: 
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         pixels[block_ptr++] = pixels[prev_block_ptr++];
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                     prev_block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* 1-color block encoding */
yading@10:         case 0x60:
yading@10:         case 0x70:
yading@10:             n_blocks = GET_BLOCK_COUNT();
yading@10:             pixel = bytestream2_get_byte(&s->gb);
yading@10: 
yading@10:             while (n_blocks--) {
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         pixels[block_ptr++] = pixel;
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* 2-color block encoding */
yading@10:         case 0x80:
yading@10:         case 0x90:
yading@10:             n_blocks = (opcode & 0x0F) + 1;
yading@10: 
yading@10:             /* figure out which color pair to use to paint the 2-color block */
yading@10:             if ((opcode & 0xF0) == 0x80) {
yading@10:                 /* fetch the next 2 colors from bytestream and store in next
yading@10:                  * available entry in the color pair table */
yading@10:                 for (i = 0; i < CPAIR; i++) {
yading@10:                     pixel = bytestream2_get_byte(&s->gb);
yading@10:                     color_table_index = CPAIR * color_pair_index + i;
yading@10:                     s->color_pairs[color_table_index] = pixel;
yading@10:                 }
yading@10:                 /* this is the base index to use for this block */
yading@10:                 color_table_index = CPAIR * color_pair_index;
yading@10:                 color_pair_index++;
yading@10:                 /* wraparound */
yading@10:                 if (color_pair_index == COLORS_PER_TABLE)
yading@10:                     color_pair_index = 0;
yading@10:             } else
yading@10:                 color_table_index = CPAIR * bytestream2_get_byte(&s->gb);
yading@10: 
yading@10:             while (n_blocks--) {
yading@10:                 color_flags = bytestream2_get_be16(&s->gb);
yading@10:                 flag_mask = 0x8000;
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         if (color_flags & flag_mask)
yading@10:                             pixel = color_table_index + 1;
yading@10:                         else
yading@10:                             pixel = color_table_index;
yading@10:                         flag_mask >>= 1;
yading@10:                         pixels[block_ptr++] = s->color_pairs[pixel];
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* 4-color block encoding */
yading@10:         case 0xA0:
yading@10:         case 0xB0:
yading@10:             n_blocks = (opcode & 0x0F) + 1;
yading@10: 
yading@10:             /* figure out which color quad to use to paint the 4-color block */
yading@10:             if ((opcode & 0xF0) == 0xA0) {
yading@10:                 /* fetch the next 4 colors from bytestream and store in next
yading@10:                  * available entry in the color quad table */
yading@10:                 for (i = 0; i < CQUAD; i++) {
yading@10:                     pixel = bytestream2_get_byte(&s->gb);
yading@10:                     color_table_index = CQUAD * color_quad_index + i;
yading@10:                     s->color_quads[color_table_index] = pixel;
yading@10:                 }
yading@10:                 /* this is the base index to use for this block */
yading@10:                 color_table_index = CQUAD * color_quad_index;
yading@10:                 color_quad_index++;
yading@10:                 /* wraparound */
yading@10:                 if (color_quad_index == COLORS_PER_TABLE)
yading@10:                     color_quad_index = 0;
yading@10:             } else
yading@10:                 color_table_index = CQUAD * bytestream2_get_byte(&s->gb);
yading@10: 
yading@10:             while (n_blocks--) {
yading@10:                 color_flags = bytestream2_get_be32(&s->gb);
yading@10:                 /* flag mask actually acts as a bit shift count here */
yading@10:                 flag_mask = 30;
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         pixel = color_table_index +
yading@10:                             ((color_flags >> flag_mask) & 0x03);
yading@10:                         flag_mask -= 2;
yading@10:                         pixels[block_ptr++] = s->color_quads[pixel];
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* 8-color block encoding */
yading@10:         case 0xC0:
yading@10:         case 0xD0:
yading@10:             n_blocks = (opcode & 0x0F) + 1;
yading@10: 
yading@10:             /* figure out which color octet to use to paint the 8-color block */
yading@10:             if ((opcode & 0xF0) == 0xC0) {
yading@10:                 /* fetch the next 8 colors from bytestream and store in next
yading@10:                  * available entry in the color octet table */
yading@10:                 for (i = 0; i < COCTET; i++) {
yading@10:                     pixel = bytestream2_get_byte(&s->gb);
yading@10:                     color_table_index = COCTET * color_octet_index + i;
yading@10:                     s->color_octets[color_table_index] = pixel;
yading@10:                 }
yading@10:                 /* this is the base index to use for this block */
yading@10:                 color_table_index = COCTET * color_octet_index;
yading@10:                 color_octet_index++;
yading@10:                 /* wraparound */
yading@10:                 if (color_octet_index == COLORS_PER_TABLE)
yading@10:                     color_octet_index = 0;
yading@10:             } else
yading@10:                 color_table_index = COCTET * bytestream2_get_byte(&s->gb);
yading@10: 
yading@10:             while (n_blocks--) {
yading@10:                 /*
yading@10:                   For this input of 6 hex bytes:
yading@10:                     01 23 45 67 89 AB
yading@10:                   Mangle it to this output:
yading@10:                     flags_a = xx012456, flags_b = xx89A37B
yading@10:                 */
yading@10:                 /* build the color flags */
yading@10:                 int val1 = bytestream2_get_be16(&s->gb);
yading@10:                 int val2 = bytestream2_get_be16(&s->gb);
yading@10:                 int val3 = bytestream2_get_be16(&s->gb);
yading@10:                 color_flags_a = ((val1 & 0xFFF0) << 8) | (val2 >> 4);
yading@10:                 color_flags_b = ((val3 & 0xFFF0) << 8) |
yading@10:                     ((val1 & 0x0F) << 8) | ((val2 & 0x0F) << 4) | (val3 & 0x0F);
yading@10: 
yading@10:                 color_flags = color_flags_a;
yading@10:                 /* flag mask actually acts as a bit shift count here */
yading@10:                 flag_mask = 21;
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     /* reload flags at third row (iteration pixel_y == 2) */
yading@10:                     if (pixel_y == 2) {
yading@10:                         color_flags = color_flags_b;
yading@10:                         flag_mask = 21;
yading@10:                     }
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         pixel = color_table_index +
yading@10:                             ((color_flags >> flag_mask) & 0x07);
yading@10:                         flag_mask -= 3;
yading@10:                         pixels[block_ptr++] = s->color_octets[pixel];
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         /* 16-color block encoding (every pixel is a different color) */
yading@10:         case 0xE0:
yading@10:             n_blocks = (opcode & 0x0F) + 1;
yading@10: 
yading@10:             while (n_blocks--) {
yading@10:                 block_ptr = row_ptr + pixel_ptr;
yading@10:                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
yading@10:                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
yading@10:                         pixels[block_ptr++] = bytestream2_get_byte(&s->gb);
yading@10:                     }
yading@10:                     block_ptr += row_inc;
yading@10:                 }
yading@10:                 ADVANCE_BLOCK();
yading@10:             }
yading@10:             break;
yading@10: 
yading@10:         case 0xF0:
yading@10:             avpriv_request_sample(s->avctx, "0xF0 opcode");
yading@10:             break;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     return;
yading@10: }
yading@10: 
yading@10: static av_cold int smc_decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     SmcContext *s = avctx->priv_data;
yading@10: 
yading@10:     s->avctx = avctx;
yading@10:     avctx->pix_fmt = AV_PIX_FMT_PAL8;
yading@10: 
yading@10:     avcodec_get_frame_defaults(&s->frame);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int smc_decode_frame(AVCodecContext *avctx,
yading@10:                              void *data, int *got_frame,
yading@10:                              AVPacket *avpkt)
yading@10: {
yading@10:     const uint8_t *buf = avpkt->data;
yading@10:     int buf_size = avpkt->size;
yading@10:     SmcContext *s = avctx->priv_data;
yading@10:     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
yading@10:     int ret;
yading@10: 
yading@10:     bytestream2_init(&s->gb, buf, buf_size);
yading@10: 
yading@10:     if ((ret = ff_reget_buffer(avctx, &s->frame)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     if (pal) {
yading@10:         s->frame.palette_has_changed = 1;
yading@10:         memcpy(s->pal, pal, AVPALETTE_SIZE);
yading@10:     }
yading@10: 
yading@10:     smc_decode_stream(s);
yading@10: 
yading@10:     *got_frame      = 1;
yading@10:     if ((ret = av_frame_ref(data, &s->frame)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     /* always report that the buffer was completely consumed */
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold int smc_decode_end(AVCodecContext *avctx)
yading@10: {
yading@10:     SmcContext *s = avctx->priv_data;
yading@10: 
yading@10:     av_frame_unref(&s->frame);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_smc_decoder = {
yading@10:     .name           = "smc",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_SMC,
yading@10:     .priv_data_size = sizeof(SmcContext),
yading@10:     .init           = smc_decode_init,
yading@10:     .close          = smc_decode_end,
yading@10:     .decode         = smc_decode_frame,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"),
yading@10: };