yading@10: /*
yading@10:  * ZeroCodec Decoder
yading@10:  *
yading@10:  * Copyright (c) 2012, Derek Buitenhuis
yading@10:  *
yading@10:  * Permission to use, copy, modify, and/or distribute this software for any
yading@10:  * purpose with or without fee is hereby granted, provided that the above
yading@10:  * copyright notice and this permission notice appear in all copies.
yading@10:  *
yading@10:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
yading@10:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
yading@10:  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
yading@10:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
yading@10:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
yading@10:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
yading@10:  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
yading@10:  */
yading@10: 
yading@10: #include <zlib.h>
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "internal.h"
yading@10: #include "libavutil/common.h"
yading@10: 
yading@10: typedef struct {
yading@10:     AVFrame  previous_frame;
yading@10:     z_stream zstream;
yading@10: } ZeroCodecContext;
yading@10: 
yading@10: static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
yading@10:                                   int *got_frame, AVPacket *avpkt)
yading@10: {
yading@10:     ZeroCodecContext *zc = avctx->priv_data;
yading@10:     AVFrame *pic         = data;
yading@10:     AVFrame *prev_pic    = &zc->previous_frame;
yading@10:     z_stream *zstream    = &zc->zstream;
yading@10:     uint8_t *prev        = prev_pic->data[0];
yading@10:     uint8_t *dst;
yading@10:     int i, j, zret, ret;
yading@10: 
yading@10:     if (avpkt->flags & AV_PKT_FLAG_KEY) {
yading@10:         pic->key_frame = 1;
yading@10:         pic->pict_type = AV_PICTURE_TYPE_I;
yading@10:     } else {
yading@10:         if (!prev) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10: 
yading@10:         prev += (avctx->height - 1) * prev_pic->linesize[0];
yading@10: 
yading@10:         pic->key_frame = 0;
yading@10:         pic->pict_type = AV_PICTURE_TYPE_P;
yading@10:     }
yading@10: 
yading@10:     zret = inflateReset(zstream);
yading@10:     if (zret != Z_OK) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     zstream->next_in  = avpkt->data;
yading@10:     zstream->avail_in = avpkt->size;
yading@10: 
yading@10:     dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
yading@10: 
yading@10:     /**
yading@10:      * ZeroCodec has very simple interframe compression. If a value
yading@10:      * is the same as the previous frame, set it to 0.
yading@10:      */
yading@10: 
yading@10:     for (i = 0; i < avctx->height; i++) {
yading@10:         zstream->next_out  = dst;
yading@10:         zstream->avail_out = avctx->width << 1;
yading@10: 
yading@10:         zret = inflate(zstream, Z_SYNC_FLUSH);
yading@10:         if (zret != Z_OK && zret != Z_STREAM_END) {
yading@10:             av_log(avctx, AV_LOG_ERROR,
yading@10:                    "Inflate failed with return code: %d.\n", zret);
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10: 
yading@10:         if (!(avpkt->flags & AV_PKT_FLAG_KEY))
yading@10:             for (j = 0; j < avctx->width << 1; j++)
yading@10:                 dst[j] += prev[j] & -!dst[j];
yading@10: 
yading@10:         prev -= prev_pic->linesize[0];
yading@10:         dst  -= pic->linesize[0];
yading@10:     }
yading@10: 
yading@10:     av_frame_unref(&zc->previous_frame);
yading@10:     if ((ret = av_frame_ref(&zc->previous_frame, pic)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     *got_frame = 1;
yading@10: 
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
yading@10: {
yading@10:     ZeroCodecContext *zc = avctx->priv_data;
yading@10: 
yading@10:     av_frame_unref(&zc->previous_frame);
yading@10: 
yading@10:     inflateEnd(&zc->zstream);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     ZeroCodecContext *zc = avctx->priv_data;
yading@10:     z_stream *zstream    = &zc->zstream;
yading@10:     int zret;
yading@10: 
yading@10:     avctx->pix_fmt             = AV_PIX_FMT_UYVY422;
yading@10:     avctx->bits_per_raw_sample = 8;
yading@10: 
yading@10:     zstream->zalloc = Z_NULL;
yading@10:     zstream->zfree  = Z_NULL;
yading@10:     zstream->opaque = Z_NULL;
yading@10: 
yading@10:     zret = inflateInit(zstream);
yading@10:     if (zret != Z_OK) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d.\n", zret);
yading@10:         return AVERROR(ENOMEM);
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_zerocodec_decoder = {
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .name           = "zerocodec",
yading@10:     .id             = AV_CODEC_ID_ZEROCODEC,
yading@10:     .priv_data_size = sizeof(ZeroCodecContext),
yading@10:     .init           = zerocodec_decode_init,
yading@10:     .decode         = zerocodec_decode_frame,
yading@10:     .close          = zerocodec_decode_close,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
yading@10: };