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FFmpeg/libavcodec/yop.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

279 lines
8.1 KiB
C

/*
* 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 "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "internal.h"
typedef struct YopDecContext {
AVCodecContext *avctx;
AVFrame *frame;
int num_pal_colors;
int first_color[2];
int frame_data_length;
uint8_t *low_nibble;
uint8_t *srcptr;
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, void *data, 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_number)
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;
}
frame->palette_has_changed = 1;
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(data, s->frame)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
const AVCodec ff_yop_decoder = {
.name = "yop",
.long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_YOP,
.priv_data_size = sizeof(YopDecContext),
.init = yop_decode_init,
.close = yop_decode_close,
.decode = yop_decode_frame,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};