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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-28 20:53:54 +02:00
FFmpeg/libavcodec/aliaspixdec.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

133 lines
4.0 KiB
C

/*
* Alias PIX image decoder
* Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@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 "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "internal.h"
#define ALIAS_HEADER_SIZE 10
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
AVFrame *f = data;
GetByteContext gb;
int width, height, ret, bits_pixel, pixel;
uint8_t *out_buf;
uint8_t count;
int x, y;
bytestream2_init(&gb, avpkt->data, avpkt->size);
if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) {
av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size);
return AVERROR_INVALIDDATA;
}
width = bytestream2_get_be16u(&gb);
height = bytestream2_get_be16u(&gb);
bytestream2_skipu(&gb, 4); // obsolete X, Y offset
bits_pixel = bytestream2_get_be16u(&gb);
if (bits_pixel == 24)
avctx->pix_fmt = AV_PIX_FMT_BGR24;
else if (bits_pixel == 8)
avctx->pix_fmt = AV_PIX_FMT_GRAY8;
else {
av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n");
return AVERROR_INVALIDDATA;
}
ret = ff_set_dimensions(avctx, width, height);
if (ret < 0)
return ret;
if (bytestream2_get_bytes_left(&gb) < width*height / 255)
return AVERROR_INVALIDDATA;
ret = ff_get_buffer(avctx, f, 0);
if (ret < 0)
return ret;
f->pict_type = AV_PICTURE_TYPE_I;
f->key_frame = 1;
x = 0;
y = 1;
out_buf = f->data[0];
while (bytestream2_get_bytes_left(&gb) > 0) {
int i;
/* set buffer at the right position at every new line */
if (x == avctx->width) {
x = 0;
out_buf = f->data[0] + f->linesize[0] * y++;
if (y > avctx->height) {
av_log(avctx, AV_LOG_ERROR,
"Ended frame decoding with %d bytes left.\n",
bytestream2_get_bytes_left(&gb));
return AVERROR_INVALIDDATA;
}
}
/* read packet and copy data */
count = bytestream2_get_byteu(&gb);
if (!count || x + count > avctx->width) {
av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count);
return AVERROR_INVALIDDATA;
}
if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
pixel = bytestream2_get_be24(&gb);
for (i = 0; i < count; i++) {
AV_WB24(out_buf, pixel);
out_buf += 3;
}
} else { // AV_PIX_FMT_GRAY8
pixel = bytestream2_get_byte(&gb);
for (i = 0; i < count; i++)
*out_buf++ = pixel;
}
x += i;
}
if (x != width || y != height) {
av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y);
return AVERROR_INVALIDDATA;
}
*got_frame = 1;
return avpkt->size;
}
const FFCodec ff_alias_pix_decoder = {
.p.name = "alias_pix",
.p.long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_ALIAS_PIX,
.p.capabilities = AV_CODEC_CAP_DR1,
.decode = decode_frame,
};