avcodec: add mvdv video decoder

1 files changed, 283 insertions, 0 deletions

diff --git a/libavcodec/midivid.c b/libavcodec/midivid.c
new file mode 100644
index 0000000000..38465c5fbc
--- /dev/null
+++ b/libavcodec/midivid.c
@@ -0,0 +1,283 @@
+/*
+ * MidiVid decoder
+ * Copyright (c) 2019 Paul B Mahol
+ *
+ * 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
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libavutil/imgutils.h"
+#include "libavutil/internal.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mem.h"
+
+#define BITSTREAM_READER_LE
+#include "avcodec.h"
+#include "get_bits.h"
+#include "bytestream.h"
+#include "internal.h"
+
+typedef struct MidiVidContext {
+    GetByteContext gb;
+
+    uint8_t *uncompressed;
+    unsigned int uncompressed_size;
+    uint8_t *skip;
+
+    AVFrame *frame;
+} MidiVidContext;
+
+static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame)
+{
+    GetByteContext *gb = &s->gb;
+    GetBitContext mask;
+    GetByteContext idx9;
+    uint16_t nb_vectors, intra_flag;
+    const uint8_t *vec;
+    const uint8_t *mask_start;
+    uint8_t *skip;
+    uint32_t mask_size;
+    int idx9bits = 0;
+    int idx9val = 0;
+    uint32_t nb_blocks;
+
+    nb_vectors = bytestream2_get_le16(gb);
+    intra_flag = bytestream2_get_le16(gb);
+    if (intra_flag) {
+        nb_blocks = (avctx->width / 2) * (avctx->height / 2);
+    } else {
+        int skip_linesize;
+
+        nb_blocks = bytestream2_get_le32(gb);
+        skip_linesize = avctx->width >> 1;
+        mask_start = gb->buffer_start + bytestream2_tell(gb);
+        mask_size = (avctx->width >> 5) * (avctx->height >> 2);
+
+        if (bytestream2_get_bytes_left(gb) < mask_size)
+            return AVERROR_INVALIDDATA;
+
+        init_get_bits8(&mask, mask_start, mask_size);
+        bytestream2_skip(gb, mask_size);
+        skip = s->skip;
+
+        for (int y = 0; y < avctx->height >> 2; y++) {
+            for (int x = 0; x < avctx->width >> 2; x++) {
+                int flag = !get_bits1(&mask);
+
+                skip[(y*2)  *skip_linesize + x*2  ] = flag;
+                skip[(y*2)  *skip_linesize + x*2+1] = flag;
+                skip[(y*2+1)*skip_linesize + x*2  ] = flag;
+                skip[(y*2+1)*skip_linesize + x*2+1] = flag;
+            }
+        }
+    }
+
+    vec = gb->buffer_start + bytestream2_tell(gb);
+    if (bytestream2_get_bytes_left(gb) < nb_vectors * 12)
+        return AVERROR_INVALIDDATA;
+    bytestream2_skip(gb, nb_vectors * 12);
+    if (nb_vectors > 256) {
+        if (bytestream2_get_bytes_left(gb) < (nb_blocks + 7) / 8)
+            return AVERROR_INVALIDDATA;
+        bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb), (nb_blocks + 7) / 8);
+        bytestream2_skip(gb, (nb_blocks + 7) / 8);
+    }
+
+    skip = s->skip;
+
+    for (int y = avctx->height - 2; y >= 0; y -= 2) {
+        uint8_t *dsty = frame->data[0] + y * frame->linesize[0];
+        uint8_t *dstu = frame->data[1] + y * frame->linesize[1];
+        uint8_t *dstv = frame->data[2] + y * frame->linesize[2];
+
+        for (int x = 0; x < avctx->width; x += 2) {
+            int idx;
+
+            if (!intra_flag && *skip++)
+                continue;
+            if (bytestream2_get_bytes_left(gb) <= 0)
+                return AVERROR_INVALIDDATA;
+            if (nb_vectors <= 256) {
+                idx = bytestream2_get_byte(gb);
+            } else {
+                if (idx9bits == 0) {
+                    idx9val = bytestream2_get_byte(&idx9);
+                    idx9bits = 8;
+                }
+                idx9bits--;
+                idx = bytestream2_get_byte(gb) | (((idx9val >> (7 - idx9bits)) & 1) << 8);
+            }
+
+            dsty[x  +frame->linesize[0]] = vec[idx * 12 + 0];
+            dsty[x+1+frame->linesize[0]] = vec[idx * 12 + 3];
+            dsty[x]                      = vec[idx * 12 + 6];
+            dsty[x+1]                    = vec[idx * 12 + 9];
+
+            dstu[x  +frame->linesize[1]] = vec[idx * 12 + 1];
+            dstu[x+1+frame->linesize[1]] = vec[idx * 12 + 4];
+            dstu[x]                      = vec[idx * 12 + 7];
+            dstu[x+1]                    = vec[idx * 12 +10];
+
+            dstv[x  +frame->linesize[2]] = vec[idx * 12 + 2];
+            dstv[x+1+frame->linesize[2]] = vec[idx * 12 + 5];
+            dstv[x]                      = vec[idx * 12 + 8];
+            dstv[x+1]                    = vec[idx * 12 +11];
+        }
+    }
+
+    return intra_flag;
+}
+
+static ptrdiff_t lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t *dst, unsigned int size)
+{
+    uint8_t *dst_start = dst;
+    uint8_t *dst_end = dst + size;
+
+    for (;bytestream2_get_bytes_left(gb) >= 3;) {
+        int op = bytestream2_get_le16(gb);
+
+        for (int i = 0; i < 16; i++) {
+            if (op & 1) {
+                int s0 = bytestream2_get_byte(gb);
+                int s1 = bytestream2_get_byte(gb);
+                int offset = ((s0 & 0xF0) << 4) | s1;
+                int length = (s0 & 0xF) + 3;
+
+                if (dst + length > dst_end ||
+                    dst - offset < dst_start)
+                    return AVERROR_INVALIDDATA;
+                if (offset > 0) {
+                    for (int j = 0; j < length; j++) {
+                        dst[j] = dst[j - offset];
+                    }
+                }
+                dst += length;
+            } else {
+                if (dst >= dst_end)
+                    return AVERROR_INVALIDDATA;
+                *dst++ = bytestream2_get_byte(gb);
+            }
+            op >>= 1;
+        }
+    }
+
+    return dst - dst_start;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data,
+                        int *got_frame, AVPacket *avpkt)
+{
+    MidiVidContext *s = avctx->priv_data;
+    GetByteContext *gb = &s->gb;
+    AVFrame *frame = s->frame;
+    int ret, key, uncompressed;
+
+    if (avpkt->size <= 13)
+        return AVERROR_INVALIDDATA;
+
+    bytestream2_init(gb, avpkt->data, avpkt->size);
+    bytestream2_skip(gb, 8);
+    uncompressed = bytestream2_get_le32(gb);
+
+    if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
+        return ret;
+
+    if (uncompressed) {
+        ret = decode_mvdv(s, avctx, frame);
+    } else {
+        av_fast_padded_malloc(&s->uncompressed, &s->uncompressed_size, 16LL * (avpkt->size - 12));
+        if (!s->uncompressed)
+            return AVERROR(ENOMEM);
+
+        ret = lzss_uncompress(s, gb, s->uncompressed, s->uncompressed_size);
+        if (ret < 0)
+            return ret;
+        bytestream2_init(gb, s->uncompressed, ret);
+        ret = decode_mvdv(s, avctx, frame);
+    }
+
+    if (ret < 0)
+        return ret;
+    key = ret;
+
+    if ((ret = av_frame_ref(data, s->frame)) < 0)
+        return ret;
+
+    frame->pict_type = key ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
+    frame->key_frame = key;
+    *got_frame = 1;
+
+    return avpkt->size;
+}
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    MidiVidContext *s = avctx->priv_data;
+    int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
+
+    if (ret < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
+               avctx->width, avctx->height);
+        return ret;
+    }
+
+    avctx->pix_fmt = AV_PIX_FMT_YUV444P;
+
+    s->frame = av_frame_alloc();
+    if (!s->frame)
+        return AVERROR(ENOMEM);
+    s->skip = av_calloc(avctx->width >> 1, avctx->height >> 1);
+    if (!s->skip)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static void decode_flush(AVCodecContext *avctx)
+{
+    MidiVidContext *s = avctx->priv_data;
+
+    av_frame_unref(s->frame);
+}
+
+static av_cold int decode_close(AVCodecContext *avctx)
+{
+    MidiVidContext *s = avctx->priv_data;
+
+    av_frame_free(&s->frame);
+    av_freep(&s->uncompressed);
+    av_freep(&s->skip);
+
+    return 0;
+}
+
+AVCodec ff_mvdv_decoder = {
+    .name           = "mvdv",
+    .long_name      = NULL_IF_CONFIG_SMALL("MidiVid VQ"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_MVDV,
+    .priv_data_size = sizeof(MidiVidContext),
+    .init           = decode_init,
+    .decode         = decode_frame,
+    .flush          = decode_flush,
+    .close          = decode_close,
+    .capabilities   = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+};