avcodec: add Gremlin Digital Video decoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 404 insertions, 0 deletions

diff --git a/libavcodec/gdv.c b/libavcodec/gdv.c
new file mode 100644
index 0000000000..095cf4c40f
--- /dev/null
+++ b/libavcodec/gdv.c
@@ -0,0 +1,404 @@
+/*
+ * Gremlin Digital Video (GDV) decoder
+ * Copyright (c) 2017 Konstantin Shishkov
+ * Copyright (c) 2017 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 "libavutil/common.h"
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+typedef struct GDVContext {
+    AVCodecContext *avctx;
+
+    GetByteContext gb;
+    GetByteContext g2;
+    PutByteContext pb;
+
+    uint32_t pal[256];
+    uint8_t *frame;
+    unsigned frame_size;
+    unsigned scale_h, scale_v;
+} GDVContext;
+
+typedef struct Bits32 {
+    uint32_t queue;
+    uint8_t  fill;
+} Bits32;
+
+#define PREAMBLE_SIZE 4096
+
+static av_cold int gdv_decode_init(AVCodecContext *avctx)
+{
+    GDVContext *gdv = avctx->priv_data;
+    int i, j, k;
+
+    avctx->pix_fmt  = AV_PIX_FMT_PAL8;
+    gdv->frame_size = avctx->width * avctx->height + PREAMBLE_SIZE;
+    gdv->frame = av_calloc(gdv->frame_size, 1);
+    if (!gdv->frame)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < 2; i++) {
+        for (j = 0; j < 256; j++) {
+            for (k = 0; k < 8; k++) {
+                gdv->frame[i * 2048 + j * 8 + k] = j;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, int scale_h)
+{
+    int i, j, y, x;
+
+    if ((gdv->scale_v == scale_v) && (gdv->scale_h == scale_h)) {
+        return;
+    }
+
+    if (gdv->scale_h && gdv->scale_v) {
+        for (j = 0; j < h; j++) {
+            int y = h - j - 1;
+            for (i = 0; i < w; i++) {
+                int x = w - i - 1;
+                dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x/2 + (y/2) * (w/2)];
+            }
+        }
+    } else if (gdv->scale_h) {
+        for (j = 0; j < h; j++) {
+            int y = h - j - 1;
+            for (x = 0; x < w; x++) {
+                dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + (y/2) * w];
+            }
+        }
+    } else if (gdv->scale_v) {
+        for (j = 0; j < h; j++) {
+            int y = h - j - 1;
+            for (i = 0; i < w; i++) {
+                int x = w - i - 1;
+                dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x/2 + y * (w/2)];
+            }
+        }
+    }
+
+    if (scale_h && scale_v) {
+        for (y = 0; y < h/2; y++) {
+            for (x = 0; x < w/2; x++) {
+                dst[PREAMBLE_SIZE + x + y * (w/2)] = dst[PREAMBLE_SIZE + x*2 + y*2 * w];
+            }
+        }
+    } else if (scale_h) {
+        for (y = 0; y < h/2; y++) {
+            for (x = 0; x < w; x++) {
+                dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + y*2 * w];
+            }
+        }
+    } else if (scale_v) {
+        for (y = 0; y < h; y++) {
+            for (x = 0; x < w/2; x++) {
+                dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x*2 + y * w];
+            }
+        }
+    }
+
+    gdv->scale_v = scale_v;
+    gdv->scale_h = scale_h;
+}
+
+static void fill_bits32(Bits32 *bits, GetByteContext *gb)
+{
+    bits->queue = bytestream2_get_le32(gb);
+    bits->fill  = 32;
+}
+
+static int read_bits32(Bits32 *bits, GetByteContext *gb, int nbits)
+{
+    int res = bits->queue & ((1 << nbits) - 1);
+
+    bits->queue >>= nbits;
+    bits->fill   -= nbits;
+    if (bits->fill <= 16) {
+        bits->queue |= bytestream2_get_le16(gb) << bits->fill;
+        bits->fill  += 16;
+    }
+
+    return res;
+}
+
+static void lz_copy(PutByteContext *pb, GetByteContext *g2, int offset, unsigned len)
+{
+    int i;
+
+    if (offset == -1) {
+        int c;
+
+        bytestream2_seek(g2, bytestream2_tell_p(pb) - 1, SEEK_SET);
+        c = bytestream2_get_byte(g2);
+        for (i = 0; i < len; i++) {
+            bytestream2_put_byte(pb, c);
+        }
+    } else if (offset < 0) {
+        int start = bytestream2_tell_p(pb) - (-offset);
+
+        bytestream2_seek(g2, start, SEEK_SET);
+        for (i = 0; i < len; i++) {
+            bytestream2_put_byte(pb, bytestream2_get_byte(g2));
+        }
+    } else {
+        int start = bytestream2_tell_p(pb) + offset;
+
+        bytestream2_seek(g2, start, SEEK_SET);
+        for (i = 0; i < len; i++) {
+            bytestream2_put_byte(pb, bytestream2_get_byte(g2));
+        }
+    }
+}
+
+static int decompress_68(AVCodecContext *avctx, unsigned skip, unsigned use8)
+{
+    GDVContext *gdv = avctx->priv_data;
+    GetByteContext *gb = &gdv->gb;
+    GetByteContext *g2 = &gdv->g2;
+    PutByteContext *pb = &gdv->pb;
+    Bits32 bits;
+
+    bytestream2_init(g2, gdv->frame, gdv->frame_size);
+    bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
+    fill_bits32(&bits, gb);
+
+    while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
+        int tag = read_bits32(&bits, gb, 2);
+        if (tag == 0) {
+            int b = read_bits32(&bits, gb, 1);
+            if (b == 0) {
+                bytestream2_put_byte(pb, bytestream2_get_byte(gb));
+            } else {
+                int i, len = 2;
+                int lbits = 0;
+                while (1) {
+                    int val;
+
+                    lbits += 1;
+                    val = read_bits32(&bits, gb, lbits);
+                    len += val;
+                    if (val != ((1 << lbits) - 1)) {
+                        break;
+                    }
+                    assert(lbits < 16);
+                }
+                for (i = 0; i < len; i++) {
+                    bytestream2_put_byte(pb, bytestream2_get_byte(gb));
+                }
+            }
+        } else if (tag == 1) {
+            int b = read_bits32(&bits, gb, 1);
+            int len;
+
+            if (b == 0) {
+                len = (read_bits32(&bits, gb, 4)) + 2;
+            } else {
+                int bb = bytestream2_get_byte(gb);
+                if ((bb & 0x80) == 0) {
+                    len = bb + 18;
+                } else {
+                    int top = (bb & 0x7F) << 8;
+                    len = top + bytestream2_get_byte(gb) + 146;
+                }
+            }
+            bytestream2_skip_p(pb, len);
+        } else if (tag == 2) {
+            int i, subtag = read_bits32(&bits, gb, 2);
+
+            if (subtag != 3) {
+                int top = (read_bits32(&bits, gb, 4)) << 8;
+                int offs = top + bytestream2_get_byte(gb);
+                if ((subtag != 0) || (offs <= 0xF80)) {
+                    int len = (subtag) + 3;
+                    lz_copy(pb, g2, (offs) - 4096, len);
+                } else {
+                    if (offs == 0xFFF) {
+                        return 0;
+                    }
+
+                    int real_off = ((offs >> 4) & 0x7) + 1;
+                    int len = ((offs & 0xF) + 2) * 2;
+                    int c1 = gdv->frame[bytestream2_tell_p(pb) - real_off];
+                    int c2 = gdv->frame[bytestream2_tell_p(pb) - real_off + 1];
+                    for (i = 0; i < len/2; i++) {
+                        bytestream2_put_byte(pb, c1);
+                        bytestream2_put_byte(pb, c2);
+                    }
+                }
+            } else {
+                int b = bytestream2_get_byte(gb);
+                int off = ((b & 0x7F)) + 1;
+                int len = ((b & 0x80) == 0) ? 2 : 3;
+
+                lz_copy(pb, g2, -off, len);
+            }
+        } else {
+            int len;
+            int off;
+            if (use8) {
+                int b = bytestream2_get_byte(gb);
+                if ((b & 0xC0) == 0xC0) {
+                    len = ((b & 0x3F)) + 8;
+                    int q = read_bits32(&bits, gb, 4);
+                    off = (q << 8) + (bytestream2_get_byte(gb)) + 1;
+                } else {
+                    int ofs1;
+                    if ((b & 0x80) == 0) {
+                        len = ((b >> 4)) + 6;
+                        ofs1 = (b & 0xF);
+                    } else {
+                        len = ((b & 0x3F)) + 14;
+                        ofs1 = read_bits32(&bits, gb, 4);
+                    }
+                    off = (ofs1 << 8) + (bytestream2_get_byte(gb)) - 4096;
+                }
+            } else {
+                int b = bytestream2_get_byte(gb);
+
+                if ((b >> 4) == 0xF) {
+                    len = bytestream2_get_byte(gb) + 21;
+                } else {
+                    len = (b >> 4) + 6;
+                }
+                int ofs1 = (b & 0xF);
+                off = (ofs1 << 8) + bytestream2_get_byte(gb) - 4096;
+            }
+            lz_copy(pb, g2, off, len);
+        }
+    }
+
+    return 0;
+}
+
+static int gdv_decode_frame(AVCodecContext *avctx, void *data,
+                            int *got_frame, AVPacket *avpkt)
+{
+    GDVContext *gdv = avctx->priv_data;
+    GetByteContext *gb = &gdv->gb;
+    PutByteContext *pb = &gdv->pb;
+    AVFrame *frame = data;
+    int ret, i, pal_size;
+    const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
+    int compression;
+    unsigned flags;
+    uint8_t *dst;
+
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+    if (pal && pal_size == AVPALETTE_SIZE)
+        memcpy(gdv->pal, pal, AVPALETTE_SIZE);
+
+    bytestream2_init(gb, avpkt->data, avpkt->size);
+    bytestream2_init_writer(pb, gdv->frame, gdv->frame_size);
+
+    flags = bytestream2_get_le32(gb);
+    compression = flags & 0xF;
+
+    rescale(gdv, gdv->frame, avctx->width, avctx->height,
+            !!(flags & 0x10), !!(flags & 0x20));
+
+    switch (compression) {
+    case 1:
+        memset(gdv->frame + PREAMBLE_SIZE, 0, gdv->frame_size - PREAMBLE_SIZE);
+    case 0:
+        for (i = 0; i < 256; i++) {
+            unsigned r = bytestream2_get_byte(gb);
+            unsigned g = bytestream2_get_byte(gb);
+            unsigned b = bytestream2_get_byte(gb);
+            gdv->pal[i] = 0xFF << 24 | r << 18 | g << 10 | b << 2;
+        }
+        break;
+    case 3:
+        break;
+    case 6:
+        ret = decompress_68(avctx, flags >> 8, 0);
+        break;
+    case 8:
+        ret = decompress_68(avctx, flags >> 8, 1);
+        break;
+    default:
+        return AVERROR_INVALIDDATA;
+    }
+
+    memcpy(frame->data[1], gdv->pal, AVPALETTE_SIZE);
+    dst = frame->data[0];
+
+    if (!gdv->scale_v && !gdv->scale_h) {
+        int sidx = PREAMBLE_SIZE, didx = 0;
+        int y, x;
+
+        for (y = 0; y < avctx->height; y++) {
+            for (x = 0; x < avctx->width; x++) {
+                dst[x+didx] = gdv->frame[x+sidx];
+            }
+            sidx += avctx->width;
+            didx += frame->linesize[0];
+        }
+    } else {
+        int sidx = PREAMBLE_SIZE, didx = 0;
+        int y, x;
+
+        for (y = 0; y < avctx->height; y++) {
+            if (!gdv->scale_v) {
+                for (x = 0; x < avctx->width; x++) {
+                    dst[didx + x] = gdv->frame[sidx + x];
+                }
+            } else {
+                for (x = 0; x < avctx->width; x++) {
+                    dst[didx + x] = gdv->frame[sidx + x/2];
+                }
+            }
+            if (!gdv->scale_h || ((y & 1) == 1)) {
+                sidx += !gdv->scale_v ? avctx->width : avctx->width/2;
+            }
+            didx += frame->linesize[0];
+        }
+    }
+
+    *got_frame = 1;
+
+    return ret < 0 ? ret : avpkt->size;
+}
+
+static av_cold int gdv_decode_close(AVCodecContext *avctx)
+{
+    GDVContext *gdv = avctx->priv_data;
+    av_freep(&gdv->frame);
+    return 0;
+}
+
+AVCodec ff_gdv_decoder = {
+    .name           = "gdv",
+    .long_name      = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_GDV,
+    .priv_data_size = sizeof(GDVContext),
+    .init           = gdv_decode_init,
+    .close          = gdv_decode_close,
+    .decode         = gdv_decode_frame,
+    .capabilities   = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
+};