--- /dev/null
+/*
+ * VBLE Decoder
+ * Copyright (c) 2011 Derek Buitenhuis
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * VBLE Decoder
+ */
+
+#define ALT_BITSTREAM_READER_LE
+
+#include "avcodec.h"
+#include "get_bits.h"
+
+typedef struct {
+ AVCodecContext *avctx;
+
+ int size;
+ int flags;
+ uint8_t *len;
+ uint8_t *val;
+} VBLEContext;
+
+static uint8_t vble_read_reverse_unary(GetBitContext *gb)
+{
+ /* At most we need to read 9 bits total to get indices up to 8 */
+ uint8_t val = show_bits(gb, 8);
+
+ if (val) {
+ val = 7 - av_log2_16bit(av_reverse[val]);
+ skip_bits(gb, val + 1);
+ return val;
+ } else {
+ skip_bits(gb, 8);
+ if (get_bits1(gb))
+ return 8;
+ }
+
+ /* Return something larger than 8 on error */
+ return UINT8_MAX;
+}
+
+static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
+{
+ int i;
+
+ /* Read all the lengths in first */
+ for (i = 0; i < ctx->size; i++) {
+ ctx->len[i] = vble_read_reverse_unary(gb);
+
+ if (ctx->len[i] == UINT8_MAX)
+ return -1;
+ }
+
+ /* For any values that have length 0 */
+ memset(ctx->val, 0, ctx->size);
+
+ for (i = 0; i < ctx->size; i++) {
+ /* Check we have enough bits left */
+ if (get_bits_left(gb) < ctx->len[i])
+ return -1;
+
+ /* get_bits can't take a length of 0 */
+ if (ctx->len[i])
+ ctx->val[i] = (1 << ctx->len[i]) + get_bits(gb, ctx->len[i]) - 1;
+ }
+
+ return 0;
+}
+
+static void vble_restore_plane(VBLEContext *ctx, int plane, int offset,
+ int width, int height)
+{
+ AVFrame *pic = ctx->avctx->coded_frame;
+ uint8_t *dst = pic->data[plane];
+ uint8_t *val = ctx->val + offset;
+ uint8_t *len = ctx->len + offset;
+ uint8_t a, b, c;
+ int stride = pic->linesize[plane];
+ int i, j;
+
+ for (i = 0; i < height; i++) {
+ for (j = 0; j < width; j++) {
+ dst[j] = (val[j] >> 1) ^ -(val[j] & 1);
+
+ /* Top line and left column are not predicted */
+ if (!j)
+ continue;
+
+ if (!i) {
+ dst[j] += dst[j - 1];
+ continue;
+ }
+
+ a = dst[j - 1];
+ b = dst[j - stride];
+ c = a + b - dst[j - 1 - stride];
+ dst[j] += mid_pred(a, b, c);
+ }
+ dst += stride;
+ val += width;
+ len += width;
+ }
+}
+
+static int vble_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
+ AVPacket *avpkt)
+{
+ VBLEContext *ctx = avctx->priv_data;
+ AVFrame *pic = avctx->coded_frame;
+ GetBitContext gb;
+ const uint8_t *src = avpkt->data;
+ int version;
+ int offset = 0;
+ int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
+
+ pic->reference = 0;
+
+ /* Clear buffer if need be */
+ if (pic->data[0])
+ avctx->release_buffer(avctx, pic);
+
+ /* Allocate buffer */
+ if (avctx->get_buffer(avctx, pic) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
+ return AVERROR(ENOMEM);
+ }
+
+ /* Set flags */
+ pic->key_frame = 1;
+ pic->pict_type = FF_I_TYPE;
+
+ /* Version should always be 1 */
+ version = AV_RL32(src);
+
+ if (version != 1) {
+ av_log(avctx, AV_LOG_ERROR, "Unsupported VBLE Version: %d\n", version);
+ return AVERROR_INVALIDDATA;
+ }
+
+ init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
+
+ /* Unpack */
+ if (vble_unpack(ctx, &gb) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* Restore planes. Should be almost identical to Huffyuv's. */
+ vble_restore_plane(ctx, 0, offset, avctx->width, avctx->height);
+
+ /* Chroma */
+ if (!(ctx->flags & CODEC_FLAG_GRAY)) {
+ offset += avctx->width * avctx->height;
+ vble_restore_plane(ctx, 1, offset, width_uv, height_uv);
+
+ offset += width_uv * height_uv;
+ vble_restore_plane(ctx, 2, offset, width_uv, height_uv);
+ }
+
+ *data_size = sizeof(AVFrame);
+ *(AVFrame *)data = *pic;
+
+ return avpkt->size;
+}
+
+static av_cold int vble_decode_close(AVCodecContext *avctx)
+{
+ VBLEContext *ctx = avctx->priv_data;
+ AVFrame *pic = avctx->coded_frame;
+
+ if (pic->data[0])
+ avctx->release_buffer(avctx, pic);
+
+ av_freep(&avctx->coded_frame);
+ av_freep(&ctx->len);
+ av_freep(&ctx->val);
+
+ return 0;
+}
+
+static av_always_inline int vble_error_close(AVCodecContext *avctx,
+ const char *message)
+{
+ av_log(avctx, AV_LOG_ERROR, message);
+ vble_decode_close(avctx);
+ return AVERROR(ENOMEM);
+}
+
+static av_cold int vble_decode_init(AVCodecContext *avctx)
+{
+ VBLEContext *ctx = avctx->priv_data;
+
+ /* Stash for later use */
+ ctx->avctx = avctx;
+ ctx->flags = avctx->flags;
+
+ avctx->pix_fmt = PIX_FMT_YUV420P;
+ avctx->bits_per_raw_sample = 8;
+ avctx->coded_frame = avcodec_alloc_frame();
+
+ if (!avctx->coded_frame)
+ return vble_error_close(avctx, "Could not allocate frame.\n");
+
+ ctx->size = avpicture_get_size(avctx->pix_fmt,
+ avctx->width, avctx->height);
+
+ ctx->len = av_malloc(ctx->size * sizeof(*ctx->len));
+
+ if (!ctx->len)
+ return vble_error_close(avctx, "Could not allocate lengths buffer.\n");
+
+ ctx->val = av_malloc(ctx->size * sizeof(*ctx->val));
+
+ if (!ctx->val)
+ return vble_error_close(avctx, "Could not allocate values buffer.\n");
+
+ return 0;
+}
+
+AVCodec ff_vble_decoder = {
+ .name = "vble",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = CODEC_ID_VBLE,
+ .priv_data_size = sizeof(VBLEContext),
+ .init = vble_decode_init,
+ .close = vble_decode_close,
+ .decode = vble_decode_frame,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
+};
projects / platform / upstream / libav.git / commitdiff