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ffmpeg/libavcodec/yop.c

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/*
* Psygnosis YOP decoder
*
* Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
* derived from the code by
* Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@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
*/
#include <string.h>
#include "libavutil/imgutils.h"
#include "libavutil/internal.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
typedef struct YopDecContext {
AVCodecContext *avctx;
AVFrame *frame;
int num_pal_colors;
int first_color[2];
int frame_data_length;
const uint8_t *low_nibble;
const uint8_t *srcptr;
const uint8_t *src_end;
uint8_t *dstptr;
uint8_t *dstbuf;
} YopDecContext;
// These tables are taken directly from:
// http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
/**
* Lookup table for painting macroblocks. Bytes 0-2 of each entry contain
* the macroblock positions to be painted (taken as (0, B0, B1, B2)).
* Byte 3 contains the number of bytes consumed on the input,
* equal to max(bytes 0-2) + 1.
*/
static const uint8_t paint_lut[15][4] =
{{1, 2, 3, 4}, {1, 2, 0, 3},
{1, 2, 1, 3}, {1, 2, 2, 3},
{1, 0, 2, 3}, {1, 0, 0, 2},
{1, 0, 1, 2}, {1, 1, 2, 3},
{0, 1, 2, 3}, {0, 1, 0, 2},
{1, 1, 0, 2}, {0, 1, 1, 2},
{0, 0, 1, 2}, {0, 0, 0, 1},
{1, 1, 1, 2},
};
/**
* Lookup table for copying macroblocks. Each entry contains the respective
* x and y pixel offset for the copy source.
*/
static const int8_t motion_vector[16][2] =
{{-4, -4}, {-2, -4},
{ 0, -4}, { 2, -4},
{-4, -2}, {-4, 0},
{-3, -3}, {-1, -3},
{ 1, -3}, { 3, -3},
{-3, -1}, {-2, -2},
{ 0, -2}, { 2, -2},
{ 4, -2}, {-2, 0},
};
static av_cold int yop_decode_close(AVCodecContext *avctx)
{
YopDecContext *s = avctx->priv_data;
av_frame_free(&s->frame);
return 0;
}
static av_cold int yop_decode_init(AVCodecContext *avctx)
{
YopDecContext *s = avctx->priv_data;
s->avctx = avctx;
if (avctx->width & 1 || avctx->height & 1 ||
av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
return AVERROR_INVALIDDATA;
}
if (avctx->extradata_size < 3) {
av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");
return AVERROR_INVALIDDATA;
}
avctx->pix_fmt = AV_PIX_FMT_PAL8;
s->num_pal_colors = avctx->extradata[0];
s->first_color[0] = avctx->extradata[1];
s->first_color[1] = avctx->extradata[2];
if (s->num_pal_colors + s->first_color[0] > 256 ||
s->num_pal_colors + s->first_color[1] > 256) {
av_log(avctx, AV_LOG_ERROR,
"Palette parameters invalid, header probably corrupt\n");
return AVERROR_INVALIDDATA;
}
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
return 0;
}
/**
* Paint a macroblock using the pattern in paint_lut.
* @param s codec context
* @param tag the tag that was in the nibble
*/
static int yop_paint_block(YopDecContext *s, int linesize, int tag)
{
if (s->src_end - s->srcptr < paint_lut[tag][3]) {
av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
return AVERROR_INVALIDDATA;
}
s->dstptr[0] = s->srcptr[0];
s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
s->dstptr[linesize] = s->srcptr[paint_lut[tag][1]];
s->dstptr[linesize + 1] = s->srcptr[paint_lut[tag][2]];
// The number of src bytes consumed is in the last part of the lut entry.
s->srcptr += paint_lut[tag][3];
return 0;
}
/**
* Copy a previously painted macroblock to the current_block.
* @param copy_tag the tag that was in the nibble
*/
static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
{
uint8_t *bufptr;
// Calculate position for the copy source
bufptr = s->dstptr + motion_vector[copy_tag][0] +
linesize * motion_vector[copy_tag][1];
if (bufptr < s->dstbuf) {
av_log(s->avctx, AV_LOG_ERROR, "File probably corrupt\n");
return AVERROR_INVALIDDATA;
}
s->dstptr[0] = bufptr[0];
s->dstptr[1] = bufptr[1];
s->dstptr[linesize] = bufptr[linesize];
s->dstptr[linesize + 1] = bufptr[linesize + 1];
return 0;
}
/**
* Return the next nibble in sequence, consuming a new byte on the input
* only if necessary.
*/
static uint8_t yop_get_next_nibble(YopDecContext *s)
{
int ret;
if (s->low_nibble) {
ret = *s->low_nibble & 0xf;
s->low_nibble = NULL;
}else {
s->low_nibble = s->srcptr++;
ret = *s->low_nibble >> 4;
}
return ret;
}
static int yop_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
int *got_frame, AVPacket *avpkt)
{
YopDecContext *s = avctx->priv_data;
AVFrame *frame = s->frame;
int tag, firstcolor, is_odd_frame;
int ret, i, x, y;
uint32_t *palette;
if (avpkt->size < 4 + 3 * s->num_pal_colors) {
av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
return AVERROR_INVALIDDATA;
}
if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
return ret;
if (!avctx->frame_num)
memset(frame->data[1], 0, AVPALETTE_SIZE);
s->dstbuf = frame->data[0];
s->dstptr = frame->data[0];
s->srcptr = avpkt->data + 4;
s->src_end = avpkt->data + avpkt->size;
s->low_nibble = NULL;
is_odd_frame = avpkt->data[0];
if(is_odd_frame>1){
av_log(avctx, AV_LOG_ERROR, "frame is too odd %d\n", is_odd_frame);
return AVERROR_INVALIDDATA;
}
firstcolor = s->first_color[is_odd_frame];
palette = (uint32_t *)frame->data[1];
for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3) {
palette[i + firstcolor] = (s->srcptr[0] << 18) |
(s->srcptr[1] << 10) |
(s->srcptr[2] << 2);
palette[i + firstcolor] |= 0xFFU << 24 |
(palette[i + firstcolor] >> 6) & 0x30303;
}
#if FF_API_PALETTE_HAS_CHANGED
FF_DISABLE_DEPRECATION_WARNINGS
frame->palette_has_changed = 1;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
for (y = 0; y < avctx->height; y += 2) {
for (x = 0; x < avctx->width; x += 2) {
if (s->srcptr - avpkt->data >= avpkt->size) {
av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
return AVERROR_INVALIDDATA;
}
tag = yop_get_next_nibble(s);
if (tag != 0xf) {
ret = yop_paint_block(s, frame->linesize[0], tag);
if (ret < 0)
return ret;
} else {
tag = yop_get_next_nibble(s);
ret = yop_copy_previous_block(s, frame->linesize[0], tag);
if (ret < 0)
return ret;
}
s->dstptr += 2;
}
s->dstptr += 2*frame->linesize[0] - x;
}
if ((ret = av_frame_ref(rframe, s->frame)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
const FFCodec ff_yop_decoder = {
.p.name = "yop",
CODEC_LONG_NAME("Psygnosis YOP Video"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_YOP,
.p.capabilities = AV_CODEC_CAP_DR1,
.priv_data_size = sizeof(YopDecContext),
.init = yop_decode_init,
.close = yop_decode_close,
FF_CODEC_DECODE_CB(yop_decode_frame),
};
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