ZeroCodec Decoder

An obscure Japanese lossless video codec, originally intended
for use with a remote desktop application.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

libavcodec/zerocodec.c

@@ -0,0 +1,183 @@
+/*
+ * 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"
+
+typedef struct {
+    AVFrame  previous_frame;
+    z_stream zstream;
+    int size;
+} ZeroCodecContext;
+
+static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
+                                  int *data_size, AVPacket *avpkt)
+{
+    ZeroCodecContext *zc = avctx->priv_data;
+    AVFrame *pic         = avctx->coded_frame;
+    AVFrame *prev_pic    = &zc->previous_frame;
+    z_stream *zstream    = &zc->zstream;
+    uint8_t *prev, *dst;
+    int i, j, zret;
+
+    pic->reference = 3;
+
+    if (avctx->get_buffer(avctx, pic) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
+        return AVERROR(ENOMEM);
+    }
+
+    zret = inflateReset(zstream);
+
+    if (zret != Z_OK) {
+        av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d\n", zret);
+        return AVERROR(EINVAL);
+    }
+
+    zstream->next_in  = avpkt->data;
+    zstream->avail_in = avpkt->size;
+
+    prev = prev_pic->data[0];
+    dst  = pic->data[0];
+
+    /**
+     * ZeroCodec has very simple interframe compression. If a value
+     * is the same as the previous frame, set it to 0.
+     */
+
+    if (avpkt->flags & AV_PKT_FLAG_KEY) {
+
+        pic->key_frame = 1;
+        pic->pict_type = AV_PICTURE_TYPE_I;
+
+        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(EINVAL);
+            }
+
+            dst += pic->linesize[0];
+        }
+    } else {
+
+        pic->key_frame = 0;
+        pic->pict_type = AV_PICTURE_TYPE_P;
+
+        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(EINVAL);
+            }
+
+            for (j = 0; j < avctx->width << 1; j++)
+                dst[j] += prev[j] & -!dst[j];
+
+            prev += prev_pic->linesize[0];
+            dst  += pic->linesize[0];
+        }
+    }
+
+    /* Release the previous buffer if need be */
+    if (prev_pic->data[0])
+        avctx->release_buffer(avctx, prev_pic);
+
+    /* Store the previouse frame for use later */
+    *prev_pic = *pic;
+
+    *data_size       = sizeof(AVFrame);
+    *(AVFrame *)data = *pic;
+
+    return avpkt->size;
+}
+
+static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
+{
+    ZeroCodecContext *zc = avctx->priv_data;
+    AVFrame *prev_pic    = &zc->previous_frame;
+
+    inflateEnd(&zc->zstream);
+
+    /* Release last frame */
+    if (prev_pic->data[0])
+        avctx->release_buffer(avctx, prev_pic);
+
+    av_freep(&avctx->coded_frame);
+
+    return 0;
+}
+
+static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
+{
+    ZeroCodecContext *zc = avctx->priv_data;
+    z_stream *zstream    = &zc->zstream;
+    int zret;
+
+    avctx->pix_fmt             = PIX_FMT_UYVY422;
+    avctx->bits_per_raw_sample = 8;
+
+    zc->size = avpicture_get_size(avctx->pix_fmt,
+                                  avctx->width, avctx->height);
+
+    zstream->zalloc = Z_NULL;
+    zstream->zfree  = Z_NULL;
+    zstream->opaque = Z_NULL;
+
+    zret = inflateInit(zstream);
+
+    if (zret != Z_OK) {
+        av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d\n", zret);
+        return AVERROR(ENOMEM);
+    }
+
+    avctx->coded_frame = avcodec_alloc_frame();
+
+    if (!avctx->coded_frame) {
+        av_log(avctx, AV_LOG_ERROR, "Could not allocate frame buffer.\n");
+        zerocodec_decode_close(avctx);
+        return AVERROR(ENOMEM);
+    }
+
+    return 0;
+}
+
+AVCodec ff_zerocodec_decoder = {
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .name           = "zerocodec",
+    .id             = CODEC_ID_ZEROCODEC,
+    .priv_data_size = sizeof(ZeroCodecContext),
+    .init           = zerocodec_decode_init,
+    .decode         = zerocodec_decode_frame,
+    .close          = zerocodec_decode_close,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
+};