Auravision Aura 2 decoder

Originally committed as revision 20915 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 138 insertions, 0 deletions

diff --git a/libavcodec/aura.c b/libavcodec/aura.c
new file mode 100644
index 0000000000..f783010223
--- /dev/null
+++ b/libavcodec/aura.c
@@ -0,0 +1,138 @@
+/*
+ * Aura 2 decoder
+ *
+ * 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
+ */
+
+/**
+ * @file libavcodec/aura.c
+ * Aura 2 decoder
+ */
+
+#include "avcodec.h"
+
+typedef struct AuraDecodeContext {
+    AVCodecContext *avctx;
+    AVFrame frame;
+} AuraDecodeContext;
+
+static av_cold int aura_decode_init(AVCodecContext *avctx)
+{
+    AuraDecodeContext *s = avctx->priv_data;
+
+    s->avctx = avctx;
+    /* width needs to be divisible by 4 for this codec to work */
+    if (avctx->width & 0x3)
+        return -1;
+    avctx->pix_fmt = PIX_FMT_YUV422P;
+
+    return 0;
+}
+
+static int aura_decode_frame(AVCodecContext *avctx,
+                             void *data, int *data_size,
+                             AVPacket *pkt)
+{
+    AuraDecodeContext *s=avctx->priv_data;
+
+    uint8_t *Y, *U, *V;
+    uint8_t val;
+    int x, y;
+    const uint8_t *buf = pkt->data;
+
+    /* prediction error tables (make it clear that they are signed values) */
+    const int8_t *delta_table = (const int8_t*)buf + 16;
+
+    if (pkt->size != 48 + avctx->height * avctx->width) {
+        av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
+               pkt->size, 48 + avctx->height * avctx->width);
+        return -1;
+    }
+
+    /* pixel data starts 48 bytes in, after 3x16-byte tables */
+    buf += 48;
+
+    if(s->frame.data[0])
+        avctx->release_buffer(avctx, &s->frame);
+
+    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
+    s->frame.reference = 0;
+    if(avctx->get_buffer(avctx, &s->frame) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+
+    Y = s->frame.data[0];
+    U = s->frame.data[1];
+    V = s->frame.data[2];
+
+    /* iterate through each line in the height */
+    for (y = 0; y < avctx->height; y++) {
+        /* reset predictors */
+        val = *buf++;
+        U[0] = val & 0xF0;
+        Y[0] = val << 4;
+        val = *buf++;
+        V[0] = val & 0xF0;
+        Y[1] = Y[0] + delta_table[val & 0xF];
+        Y += 2; U++; V++;
+
+        /* iterate through the remaining pixel groups (4 pixels/group) */
+        for (x = 1; x < (avctx->width >> 1); x++) {
+            val = *buf++;
+            U[0] = U[-1] + delta_table[val >> 4];
+            Y[0] = Y[-1] + delta_table[val & 0xF];
+            val = *buf++;
+            V[0] = V[-1] + delta_table[val >> 4];
+            Y[1] = Y[ 0] + delta_table[val & 0xF];
+            Y += 2; U++; V++;
+        }
+        Y += s->frame.linesize[0] -  avctx->width;
+        U += s->frame.linesize[1] - (avctx->width >> 1);
+        V += s->frame.linesize[2] - (avctx->width >> 1);
+    }
+
+    *data_size=sizeof(AVFrame);
+    *(AVFrame*)data= s->frame;
+
+    return pkt->size;
+}
+
+static av_cold int aura_decode_end(AVCodecContext *avctx)
+{
+    AuraDecodeContext *s = avctx->priv_data;
+
+    if (s->frame.data[0])
+        avctx->release_buffer(avctx, &s->frame);
+
+    return 0;
+}
+
+AVCodec aura2_decoder = {
+    "aura2",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_AURA2,
+    sizeof(AuraDecodeContext),
+    aura_decode_init,
+    NULL,
+    aura_decode_end,
+    aura_decode_frame,
+    CODEC_CAP_DR1,
+    NULL,
+    .long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
+};
+