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ffmpeg/libavcodec/rpza.c

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/*
* Quicktime Video (RPZA) Video Decoder
* Copyright (C) 2003 the ffmpeg project
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* QT RPZA Video Decoder by Roberto Togni
* For more information about the RPZA format, visit:
* http://www.pcisys.net/~melanson/codecs/
*
* The RPZA decoder outputs RGB555 colorspace data.
*
* Note that this decoder reads big endian RGB555 pixel values from the
* bytestream, arranges them in the host's endian order, and outputs
* them to the final rendered map in the same host endian order. This is
* intended behavior as the ffmpeg documentation states that RGB555 pixels
* shall be stored in native CPU endianness.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
typedef struct RpzaContext {
AVCodecContext *avctx;
AVFrame frame;
const unsigned char *buf;
int size;
} RpzaContext;
#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_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
return; \
} \
}
static void rpza_decode_stream(RpzaContext *s)
{
int width = s->avctx->width;
int stride = s->frame.linesize[0] / 2;
int row_inc = stride - 4;
int stream_ptr = 0;
int chunk_size;
unsigned char opcode;
int n_blocks;
unsigned short colorA = 0, colorB;
unsigned short color4[4];
unsigned char index, idx;
unsigned short ta, tb;
unsigned short *pixels = (unsigned short *)s->frame.data[0];
int row_ptr = 0;
int pixel_ptr = 0;
int block_ptr;
int pixel_x, pixel_y;
int total_blocks;
/* First byte is always 0xe1. Warn if it's different */
if (s->buf[stream_ptr] != 0xe1)
av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
s->buf[stream_ptr]);
/* Get chunk size, ingnoring first byte */
chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
stream_ptr += 4;
/* If length mismatch use size from MOV file and try to decode anyway */
if (chunk_size != s->size)
av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
chunk_size = s->size;
/* Number of 4x4 blocks in frame. */
total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
/* Process chunk data */
while (stream_ptr < chunk_size) {
opcode = s->buf[stream_ptr++]; /* Get opcode */
n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
/* If opcode MSbit is 0, we need more data to decide what to do */
if ((opcode & 0x80) == 0) {
colorA = (opcode << 8) | (s->buf[stream_ptr++]);
opcode = 0;
if ((s->buf[stream_ptr] & 0x80) != 0) {
/* Must behave as opcode 110xxxxx, using colorA computed
* above. Use fake opcode 0x20 to enter switch block at
* the right place */
opcode = 0x20;
n_blocks = 1;
}
}
switch (opcode & 0xe0) {
/* Skip blocks */
case 0x80:
while (n_blocks--) {
ADVANCE_BLOCK();
}
break;
/* Fill blocks with one color */
case 0xa0:
colorA = AV_RB16 (&s->buf[stream_ptr]);
stream_ptr += 2;
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] = colorA;
block_ptr++;
}
block_ptr += row_inc;
}
ADVANCE_BLOCK();
}
break;
/* Fill blocks with 4 colors */
case 0xc0:
colorA = AV_RB16 (&s->buf[stream_ptr]);
stream_ptr += 2;
case 0x20:
colorB = AV_RB16 (&s->buf[stream_ptr]);
stream_ptr += 2;
/* sort out the colors */
color4[0] = colorB;
color4[1] = 0;
color4[2] = 0;
color4[3] = colorA;
/* red components */
ta = (colorA >> 10) & 0x1F;
tb = (colorB >> 10) & 0x1F;
color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
/* green components */
ta = (colorA >> 5) & 0x1F;
tb = (colorB >> 5) & 0x1F;
color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
/* blue components */
ta = colorA & 0x1F;
tb = colorB & 0x1F;
color4[1] |= ((11 * ta + 21 * tb) >> 5);
color4[2] |= ((21 * ta + 11 * tb) >> 5);
while (n_blocks--) {
block_ptr = row_ptr + pixel_ptr;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
index = s->buf[stream_ptr++];
for (pixel_x = 0; pixel_x < 4; pixel_x++){
idx = (index >> (2 * (3 - pixel_x))) & 0x03;
pixels[block_ptr] = color4[idx];
block_ptr++;
}
block_ptr += row_inc;
}
ADVANCE_BLOCK();
}
break;
/* Fill block with 16 colors */
case 0x00:
block_ptr = row_ptr + pixel_ptr;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++){
/* We already have color of upper left pixel */
if ((pixel_y != 0) || (pixel_x !=0)) {
colorA = AV_RB16 (&s->buf[stream_ptr]);
stream_ptr += 2;
}
pixels[block_ptr] = colorA;
block_ptr++;
}
block_ptr += row_inc;
}
ADVANCE_BLOCK();
break;
/* Unknown opcode */
default:
av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
" Skip remaining %d bytes of chunk data.\n", opcode,
chunk_size - stream_ptr);
return;
} /* Opcode switch */
}
}
static av_cold int rpza_decode_init(AVCodecContext *avctx)
{
RpzaContext *s = avctx->priv_data;
s->avctx = avctx;
avctx->pix_fmt = PIX_FMT_RGB555;
s->frame.data[0] = NULL;
return 0;
}
static int rpza_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
RpzaContext *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;
if (avctx->reget_buffer(avctx, &s->frame)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
rpza_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 rpza_decode_end(AVCodecContext *avctx)
{
RpzaContext *s = avctx->priv_data;
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec ff_rpza_decoder = {
.name = "rpza",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_RPZA,
.priv_data_size = sizeof(RpzaContext),
.init = rpza_decode_init,
.close = rpza_decode_end,
.decode = rpza_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
};
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