ffmpeg/libavcodec/zerocodec.c

150 lines
4.4 KiB
C

/*
* ZeroCodec Decoder
*
* Copyright (c) 2012, Derek Buitenhuis
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <zlib.h>
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#include "zlib_wrapper.h"
#include "libavutil/common.h"
typedef struct ZeroCodecContext {
AVFrame *previous_frame;
FFZStream zstream;
} ZeroCodecContext;
static int zerocodec_decode_frame(AVCodecContext *avctx, AVFrame *pic,
int *got_frame, AVPacket *avpkt)
{
ZeroCodecContext *zc = avctx->priv_data;
AVFrame *prev_pic = zc->previous_frame;
z_stream *const zstream = &zc->zstream.zstream;
uint8_t *prev = prev_pic->data[0];
uint8_t *dst;
int i, j, zret, ret;
if (avpkt->flags & AV_PKT_FLAG_KEY) {
pic->flags |= AV_FRAME_FLAG_KEY;
pic->pict_type = AV_PICTURE_TYPE_I;
} else {
if (!prev) {
av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
return AVERROR_INVALIDDATA;
}
prev += (avctx->height - 1) * prev_pic->linesize[0];
pic->flags &= ~AV_FRAME_FLAG_KEY;
pic->pict_type = AV_PICTURE_TYPE_P;
}
zret = inflateReset(zstream);
if (zret != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
return AVERROR_INVALIDDATA;
}
if ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
zstream->next_in = avpkt->data;
zstream->avail_in = avpkt->size;
dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
/**
* ZeroCodec has very simple interframe compression. If a value
* is the same as the previous frame, set it to 0.
*/
for (i = 0; i < avctx->height; i++) {
zstream->next_out = dst;
zstream->avail_out = avctx->width << 1;
zret = inflate(zstream, Z_SYNC_FLUSH);
if (zret != Z_OK && zret != Z_STREAM_END) {
av_log(avctx, AV_LOG_ERROR,
"Inflate failed with return code: %d.\n", zret);
return AVERROR_INVALIDDATA;
}
if (!(avpkt->flags & AV_PKT_FLAG_KEY)) {
for (j = 0; j < avctx->width << 1; j++)
dst[j] += prev[j] & -!dst[j];
prev -= prev_pic->linesize[0];
}
dst -= pic->linesize[0];
}
av_frame_unref(zc->previous_frame);
if ((ret = av_frame_ref(zc->previous_frame, pic)) < 0)
return ret;
*got_frame = 1;
return avpkt->size;
}
static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
{
ZeroCodecContext *zc = avctx->priv_data;
av_frame_free(&zc->previous_frame);
ff_inflate_end(&zc->zstream);
return 0;
}
static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
{
ZeroCodecContext *zc = avctx->priv_data;
avctx->pix_fmt = AV_PIX_FMT_UYVY422;
avctx->bits_per_raw_sample = 8;
zc->previous_frame = av_frame_alloc();
if (!zc->previous_frame)
return AVERROR(ENOMEM);
return ff_inflate_init(&zc->zstream, avctx);
}
static void zerocodec_decode_flush(AVCodecContext *avctx)
{
ZeroCodecContext *zc = avctx->priv_data;
av_frame_unref(zc->previous_frame);
}
const FFCodec ff_zerocodec_decoder = {
.p.type = AVMEDIA_TYPE_VIDEO,
.p.name = "zerocodec",
CODEC_LONG_NAME("ZeroCodec Lossless Video"),
.p.id = AV_CODEC_ID_ZEROCODEC,
.priv_data_size = sizeof(ZeroCodecContext),
.init = zerocodec_decode_init,
FF_CODEC_DECODE_CB(zerocodec_decode_frame),
.flush = zerocodec_decode_flush,
.close = zerocodec_decode_close,
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};