TechSmith Screen Codec 2 decoder

1 files changed, 382 insertions, 0 deletions

diff --git a/libavcodec/tscc2.c b/libavcodec/tscc2.c
new file mode 100644
index 0000000000..7fd87fd5cb
--- /dev/null
+++ b/libavcodec/tscc2.c
@@ -0,0 +1,382 @@
+/*
+ * TechSmith Screen Codec 2 (aka Dora) decoder
+ * Copyright (c) 2012 Konstantin Shishkov
+ *
+ * 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
+ * TechSmith Screen Codec 2 decoder
+ */
+
+#define BITSTREAM_READER_LE
+#include "avcodec.h"
+#include "get_bits.h"
+#include "bytestream.h"
+#include "tscc2data.h"
+
+typedef struct TSCC2Context {
+    AVCodecContext *avctx;
+    AVFrame        pic;
+    int            mb_width, mb_height;
+    uint8_t        *slice_quants;
+    int            quant[2];
+    int            q[2][3];
+    GetBitContext  gb;
+
+    VLC            dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
+    int            block[16];
+} TSCC2Context;
+
+static av_cold void free_vlcs(TSCC2Context *c)
+{
+    int i;
+
+    ff_free_vlc(&c->dc_vlc);
+    for (i = 0; i < NUM_VLC_SETS; i++) {
+        ff_free_vlc(c->nc_vlc + i);
+        ff_free_vlc(c->ac_vlc + i);
+    }
+}
+
+static av_cold int init_vlcs(TSCC2Context *c)
+{
+    int i, ret;
+
+    ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT,
+                             tscc2_dc_vlc_bits,  1, 1,
+                             tscc2_dc_vlc_codes, 2, 2,
+                             tscc2_dc_vlc_syms,  2, 2, INIT_VLC_LE);
+    if (ret)
+        return ret;
+
+    for (i = 0; i < NUM_VLC_SETS; i++) {
+        ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16,
+                                 tscc2_nc_vlc_bits[i],  1, 1,
+                                 tscc2_nc_vlc_codes[i], 2, 2,
+                                 tscc2_nc_vlc_syms,     1, 1, INIT_VLC_LE);
+        if (ret) {
+            free_vlcs(c);
+            return ret;
+        }
+        ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
+                                 tscc2_ac_vlc_bits[i],  1, 1,
+                                 tscc2_ac_vlc_codes[i], 2, 2,
+                                 tscc2_ac_vlc_syms[i],  2, 2, INIT_VLC_LE);
+        if (ret) {
+            free_vlcs(c);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+#define DEQUANT(val, q) ((q * val + 0x80) >> 8)
+#define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
+    OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3));  \
+    OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1));  \
+    OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s3));  \
+    OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3));  \
+
+#define COL_OP(a, b)  a = b
+#define ROW_OP(a, b)  a = av_clip_uint8((((b) + 0x20) >> 6) + 0x80)
+
+static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
+{
+    int i;
+    int tblk[4 * 4];
+    int t0, t1, t2, t3;
+
+    for (i = 0; i < 4; i++) {
+        t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
+        t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
+        t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
+        t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
+        DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
+              tblk[2 * 4 + i], tblk[3 * 4 + i],
+              t0, t1, t2, t3, COL_OP);
+    }
+    for (i = 0; i < 4; i++) {
+        DCT1D(dst[0], dst[1], dst[2], dst[3],
+              tblk[i * 4 + 0], tblk[i * 4 + 1],
+              tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
+        dst += stride;
+    }
+}
+
+static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
+                           uint8_t *dst, int stride, int plane)
+{
+    GetBitContext *gb = &c->gb;
+    int prev_dc, dc, nc, ac, bpos, val;
+    int i, j, k, l;
+
+    if (get_bits1(gb)) {
+        if (get_bits1(gb)) {
+            val = get_bits(gb, 8);
+            for (i = 0; i < 8; i++, dst += stride)
+                memset(dst, val, 16);
+        } else {
+            if (get_bits_left(gb) < 16 * 8 * 8)
+                return AVERROR_INVALIDDATA;
+            for (i = 0; i < 8; i++) {
+                for (j = 0; j < 16; j++)
+                    dst[j] = get_bits(gb, 8);
+                dst += stride;
+            }
+        }
+        return 0;
+    }
+
+    prev_dc = 0;
+    for (j = 0; j < 2; j++) {
+        for (k = 0; k < 4; k++) {
+            if (!(j | k)) {
+                dc = get_bits(gb, 8);
+            } else {
+                dc = get_vlc2(gb, c->dc_vlc.table, 9, 2);
+                if (dc == -1)
+                    return AVERROR_INVALIDDATA;
+                if (dc == 0x100)
+                    dc = get_bits(gb, 8);
+            }
+            dc          = (dc + prev_dc) & 0xFF;
+            prev_dc     = dc;
+            c->block[0] = dc - 0x80;
+
+            nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1);
+            if (nc == -1)
+                return AVERROR_INVALIDDATA;
+
+            bpos = 1;
+            memset(c->block + 1, 0, 15 * sizeof(*c->block));
+            for (l = 0; l < nc; l++) {
+                ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2);
+                if (ac == -1)
+                    return AVERROR_INVALIDDATA;
+                if (ac == 0x1000)
+                    ac = get_bits(gb, 12);
+                bpos += ac & 0xF;
+                if (bpos >= 64)
+                    return AVERROR_INVALIDDATA;
+                val = sign_extend(ac >> 4, 8);
+                c->block[tscc2_zigzag[bpos++]] = val;
+            }
+            tscc2_idct4_put(c->block, q, dst + k * 4, stride);
+        }
+        dst += 4 * stride;
+    }
+    return 0;
+}
+
+static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
+                              const uint8_t *buf, int buf_size)
+{
+    int i, mb_x, q, ret;
+    int off;
+
+    init_get_bits(&c->gb, buf, buf_size * 8);
+
+    for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
+        q = c->slice_quants[mb_x + c->mb_width * mb_y];
+
+        if (q == 0 || q == 3) // skip block
+            continue;
+        for (i = 0; i < 3; i++) {
+            off = mb_x * 16 + mb_y * 8 * c->pic.linesize[i];
+            ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
+                                  c->pic.data[i] + off, c->pic.linesize[i], i);
+            if (ret)
+                return ret;
+        }
+    }
+
+    return 0;
+}
+
+static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
+                              int *data_size, AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
+    TSCC2Context *c = avctx->priv_data;
+    GetByteContext gb;
+    uint32_t frame_type, size;
+    int i, val, len, pos = 0;
+    int num_mb = c->mb_width * c->mb_height;
+    int ret;
+
+    bytestream2_init(&gb, buf, buf_size);
+    frame_type = bytestream2_get_byte(&gb);
+    if (frame_type > 1) {
+        av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %d\n", frame_type);
+        return AVERROR_INVALIDDATA;
+    }
+
+    c->pic.reference    = 3;
+    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
+                          FF_BUFFER_HINTS_REUSABLE;
+    if ((ret = avctx->reget_buffer(avctx, &c->pic)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
+        return ret;
+    }
+
+    if (frame_type == 0) {
+        *data_size      = sizeof(AVFrame);
+        *(AVFrame*)data = c->pic;
+
+        return buf_size;
+    }
+
+    if (bytestream2_get_bytes_left(&gb) < 4) {
+        av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    c->quant[0] = bytestream2_get_byte(&gb);
+    c->quant[1] = bytestream2_get_byte(&gb);
+    if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
+        c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
+        av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
+               c->quant[0], c->quant[1]);
+        return AVERROR_INVALIDDATA;
+    }
+
+    for (i = 0; i < 3; i++) {
+        c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
+        c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
+    }
+
+    bytestream2_skip(&gb, 1);
+
+    size = bytestream2_get_le32(&gb);
+    if (size > bytestream2_get_bytes_left(&gb)) {
+        av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    for (i = 0; i < size; i++) {
+        val   = bytestream2_get_byte(&gb);
+        len   = val & 0x3F;
+        val >>= 6;
+        if (pos + len > num_mb) {
+            av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
+            return AVERROR_INVALIDDATA;
+        }
+        memset(c->slice_quants + pos, val, len);
+        pos += len;
+    }
+    if (pos < num_mb) {
+        av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
+               pos, num_mb);
+        return AVERROR_INVALIDDATA;
+    }
+
+    for (i = 0; i < c->mb_height; i++) {
+        size = bytestream2_peek_byte(&gb);
+        if (size & 1) {
+            size = bytestream2_get_byte(&gb) - 1;
+        } else {
+            size = bytestream2_get_le32(&gb) >> 1;
+        }
+        if (!size) {
+            int skip_row = 1, j, off = i * c->mb_width;
+            for (j = 0; j < c->mb_width; j++) {
+                if (c->slice_quants[off + i] == 1 ||
+                    c->slice_quants[off + i] == 2) {
+                    skip_row = 0;
+                    break;
+                }
+            }
+            if (!skip_row) {
+                av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
+                return AVERROR_INVALIDDATA;
+            }
+        }
+        if (bytestream2_get_bytes_left(&gb) < size) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%d/%d)\n",
+                   size, bytestream2_get_bytes_left(&gb));
+            return AVERROR_INVALIDDATA;
+        }
+        ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
+        if (ret) {
+            av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
+            return ret;
+        }
+        bytestream2_skip(&gb, size);
+    }
+
+    *data_size      = sizeof(AVFrame);
+    *(AVFrame*)data = c->pic;
+
+    /* always report that the buffer was completely consumed */
+    return buf_size;
+}
+
+static av_cold int tscc2_decode_init(AVCodecContext *avctx)
+{
+    TSCC2Context * const c = avctx->priv_data;
+    int ret;
+
+    c->avctx = avctx;
+
+    avctx->pix_fmt = PIX_FMT_YUV444P;
+
+    if ((ret = init_vlcs(c)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
+        return ret;
+    }
+
+    c->mb_width     = FFALIGN(avctx->width,  16) >> 4;
+    c->mb_height    = FFALIGN(avctx->height,  8) >> 3;
+    c->slice_quants = av_malloc(c->mb_width * c->mb_height);
+    if (!c->slice_quants) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
+        free_vlcs(c);
+        return AVERROR(ENOMEM);
+    }
+
+    avctx->coded_frame = &c->pic;
+
+    return 0;
+}
+
+static av_cold int tscc2_decode_end(AVCodecContext *avctx)
+{
+    TSCC2Context * const c = avctx->priv_data;
+
+    if (c->pic.data[0])
+        avctx->release_buffer(avctx, &c->pic);
+    av_freep(&c->slice_quants);
+    free_vlcs(c);
+
+    return 0;
+}
+
+AVCodec ff_tscc2_decoder = {
+    .name           = "tscc2",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_TSCC2,
+    .priv_data_size = sizeof(TSCC2Context),
+    .init           = tscc2_decode_init,
+    .close          = tscc2_decode_end,
+    .decode         = tscc2_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
+};