TDSC decoder

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

1 files changed, 627 insertions, 0 deletions

diff --git a/libavcodec/tdsc.c b/libavcodec/tdsc.c
new file mode 100644
index 0000000000..b46a3c1c63
--- /dev/null
+++ b/libavcodec/tdsc.c
@@ -0,0 +1,627 @@
+/*
+ * TDSC decoder
+ * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
+ *
+ * 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
+ * TDSC decoder
+ *
+ * Fourcc: TSDC
+ *
+ * TDSC is very simple. It codes picture by tiles, storing them in raw BGR24
+ * format or compressing them in JPEG. Frames can be full pictures or just
+ * updates to the previous frame. Cursor is found in its own frame or at the
+ * bottom of the picture. Every frame is then packed with zlib.
+ *
+ * Supports: BGR24
+ */
+
+#include <stdint.h>
+#include <zlib.h>
+
+#include "libavutil/imgutils.h"
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+#define BITMAPINFOHEADER_SIZE 0x28
+#define TDSF_HEADER_SIZE      0x56
+#define TDSB_HEADER_SIZE      0x08
+
+typedef struct TDSCContext {
+    AVCodecContext *jpeg_avctx;   // wrapper context for MJPEG
+
+    int width, height;
+    GetByteContext gbc;
+
+    AVFrame *refframe;          // full decoded frame (without cursor)
+    AVFrame *jpgframe;          // decoded JPEG tile
+    uint8_t *tilebuffer;        // buffer containing tile data
+
+    /* zlib interation */
+    uint8_t *deflatebuffer;
+    uLongf deflatelen;
+
+    /* All that is cursor */
+    uint8_t    *cursor;
+    int        cursor_stride;
+    int        cursor_w, cursor_h, cursor_x, cursor_y;
+    int        cursor_hot_x, cursor_hot_y;
+} TDSCContext;
+
+/* 1 byte bits, 1 byte planes, 2 bytes format (probably) */
+enum TDSCCursorFormat {
+    CUR_FMT_MONO = 0x01010004,
+    CUR_FMT_BGRA = 0x20010004,
+    CUR_FMT_RGBA = 0x20010008,
+};
+
+static av_cold int tdsc_close(AVCodecContext *avctx)
+{
+    TDSCContext *ctx = avctx->priv_data;
+
+    av_frame_free(&ctx->refframe);
+    av_frame_free(&ctx->jpgframe);
+    av_freep(&ctx->deflatebuffer);
+    av_freep(&ctx->tilebuffer);
+    av_freep(&ctx->cursor);
+    avcodec_free_context(&ctx->jpeg_avctx);
+
+    return 0;
+}
+
+static av_cold int tdsc_init(AVCodecContext *avctx)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    const AVCodec *codec;
+    int ret;
+
+    avctx->pix_fmt = AV_PIX_FMT_BGR24;
+
+    /* These needs to be set to estimate buffer and frame size */
+    if (!(avctx->width && avctx->height)) {
+        av_log(avctx, AV_LOG_ERROR, "Video size not set.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* This value should be large enough for a RAW-only frame plus headers */
+    ctx->deflatelen = avctx->width * avctx->height * (3 + 1);
+    ret = av_reallocp(&ctx->deflatebuffer, ctx->deflatelen);
+    if (ret < 0)
+        return ret;
+
+    /* Allocate reference and JPEG frame */
+    ctx->refframe = av_frame_alloc();
+    ctx->jpgframe = av_frame_alloc();
+    if (!ctx->refframe || !ctx->jpgframe)
+        return AVERROR(ENOMEM);
+
+    /* Prepare everything needed for JPEG decoding */
+    codec = avcodec_find_decoder(AV_CODEC_ID_MJPEG);
+    if (!codec)
+        return AVERROR_BUG;
+    ctx->jpeg_avctx = avcodec_alloc_context3(codec);
+    if (!ctx->jpeg_avctx)
+        return AVERROR(ENOMEM);
+    ctx->jpeg_avctx->flags = avctx->flags;
+    ctx->jpeg_avctx->flags2 = avctx->flags2;
+    ctx->jpeg_avctx->dct_algo = avctx->dct_algo;
+    ctx->jpeg_avctx->idct_algo = avctx->idct_algo;;
+    ret = avcodec_open2(ctx->jpeg_avctx, codec, NULL);
+    if (ret < 0)
+        return ret;
+
+    /* Set the output pixel format on the reference frame */
+    ctx->refframe->format = avctx->pix_fmt;
+
+    return 0;
+}
+
+#define APPLY_ALPHA(src, new, alpha) \
+    src = (src * (256 - alpha) + new * alpha) >> 8
+
+/* Paint a region over a buffer, without drawing out of its bounds. */
+static void tdsc_paint_cursor(AVCodecContext *avctx, uint8_t *dst, int stride)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    const uint8_t *cursor = ctx->cursor;
+    int x = ctx->cursor_x - ctx->cursor_hot_x;
+    int y = ctx->cursor_y - ctx->cursor_hot_y;
+    int w = ctx->cursor_w;
+    int h = ctx->cursor_h;
+    int i, j;
+
+    if (!ctx->cursor)
+        return;
+
+    if (x + w > ctx->width)
+        w = ctx->width - x;
+    if (y + h > ctx->height)
+        h = ctx->height - y;
+    if (x < 0) {
+        w      +=  x;
+        cursor += -x * 4;
+    } else {
+        dst    +=  x * 3;
+    }
+    if (y < 0) {
+        h      +=  y;
+        cursor += -y * ctx->cursor_stride;
+    } else {
+        dst    +=  y * stride;
+    }
+    if (w < 0 || h < 0)
+        return;
+
+    for (j = 0; j < h; j++) {
+        for (i = 0; i < w; i++) {
+            uint8_t alpha = cursor[i * 4];
+            APPLY_ALPHA(dst[i * 3 + 0], cursor[i * 4 + 1], alpha);
+            APPLY_ALPHA(dst[i * 3 + 1], cursor[i * 4 + 2], alpha);
+            APPLY_ALPHA(dst[i * 3 + 2], cursor[i * 4 + 3], alpha);
+        }
+        dst    += stride;
+        cursor += ctx->cursor_stride;
+    }
+}
+
+/* Load cursor data and store it in ABGR mode. */
+static int tdsc_load_cursor(AVCodecContext *avctx)
+{
+    TDSCContext *ctx  = avctx->priv_data;
+    int i, j, k, ret, bits, cursor_fmt;
+    uint8_t *dst;
+
+    ctx->cursor_hot_x = bytestream2_get_le16(&ctx->gbc);
+    ctx->cursor_hot_y = bytestream2_get_le16(&ctx->gbc);
+    ctx->cursor_w     = bytestream2_get_le16(&ctx->gbc);
+    ctx->cursor_h     = bytestream2_get_le16(&ctx->gbc);
+
+    ctx->cursor_stride = FFALIGN(ctx->cursor_w, 32) * 4;
+    cursor_fmt = bytestream2_get_le32(&ctx->gbc);
+
+    if (ctx->cursor_x >= avctx->width || ctx->cursor_y >= avctx->height) {
+        av_log(avctx, AV_LOG_ERROR,
+               "Invalid cursor position (%d.%d outside %dx%d).\n",
+               ctx->cursor_x, ctx->cursor_y, avctx->width, avctx->height);
+        return AVERROR_INVALIDDATA;
+    }
+    if (ctx->cursor_w < 1 || ctx->cursor_w > 256 ||
+        ctx->cursor_h < 1 || ctx->cursor_h > 256) {
+        av_log(avctx, AV_LOG_ERROR,
+               "Invalid cursor dimensions %dx%d.\n",
+               ctx->cursor_w, ctx->cursor_h);
+        return AVERROR_INVALIDDATA;
+    }
+    if (ctx->cursor_hot_x > ctx->cursor_w ||
+        ctx->cursor_hot_y > ctx->cursor_h) {
+        av_log(avctx, AV_LOG_WARNING, "Invalid hotspot position %d.%d.\n",
+               ctx->cursor_hot_x, ctx->cursor_hot_y);
+        ctx->cursor_hot_x = FFMIN(ctx->cursor_hot_x, ctx->cursor_w - 1);
+        ctx->cursor_hot_y = FFMIN(ctx->cursor_hot_y, ctx->cursor_h - 1);
+    }
+
+    ret = av_reallocp(&ctx->cursor, ctx->cursor_stride * ctx->cursor_h);
+    if (ret < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot allocate cursor buffer.\n");
+        return ret;
+    }
+
+    dst = ctx->cursor;
+    /* here data is packed in BE */
+    switch (cursor_fmt) {
+    case CUR_FMT_MONO:
+        for (j = 0; j < ctx->cursor_h; j++) {
+            for (i = 0; i < ctx->cursor_w; i += 32) {
+                bits = bytestream2_get_be32(&ctx->gbc);
+                for (k = 0; k < 32; k++) {
+                    dst[0] = !!(bits & 0x80000000);
+                    dst   += 4;
+                    bits <<= 1;
+                }
+            }
+            dst += ctx->cursor_stride - ctx->cursor_w * 4;
+        }
+
+        dst = ctx->cursor;
+        for (j = 0; j < ctx->cursor_h; j++) {
+            for (i = 0; i < ctx->cursor_w; i += 32) {
+                bits = bytestream2_get_be32(&ctx->gbc);
+                for (k = 0; k < 32; k++) {
+                    int mask_bit = !!(bits & 0x80000000);
+                    switch (dst[0] * 2 + mask_bit) {
+                    case 0:
+                        dst[0] = 0xFF;
+                        dst[1] = 0x00;
+                        dst[2] = 0x00;
+                        dst[3] = 0x00;
+                        break;
+                    case 1:
+                        dst[0] = 0xFF;
+                        dst[1] = 0xFF;
+                        dst[2] = 0xFF;
+                        dst[3] = 0xFF;
+                        break;
+                    default:
+                        dst[0] = 0x00;
+                        dst[1] = 0x00;
+                        dst[2] = 0x00;
+                        dst[3] = 0x00;
+                    }
+                    dst   += 4;
+                    bits <<= 1;
+                }
+            }
+            dst += ctx->cursor_stride - ctx->cursor_w * 4;
+        }
+        break;
+    case CUR_FMT_BGRA:
+    case CUR_FMT_RGBA:
+        /* Skip monochrome version of the cursor */
+        bytestream2_skip(&ctx->gbc,
+                         ctx->cursor_h * (FFALIGN(ctx->cursor_w, 32) >> 3));
+        if (cursor_fmt & 8) { // RGBA -> ABGR
+            for (j = 0; j < ctx->cursor_h; j++) {
+                for (i = 0; i < ctx->cursor_w; i++) {
+                    int val = bytestream2_get_be32(&ctx->gbc);
+                    *dst++ = val >> 24;
+                    *dst++ = val >> 16;
+                    *dst++ = val >>  8;
+                    *dst++ = val >>  0;
+                }
+                dst += ctx->cursor_stride - ctx->cursor_w * 4;
+            }
+        } else { // BGRA -> ABGR
+            for (j = 0; j < ctx->cursor_h; j++) {
+                for (i = 0; i < ctx->cursor_w; i++) {
+                    int val = bytestream2_get_be32(&ctx->gbc);
+                    *dst++ = val >>  0;
+                    *dst++ = val >> 24;
+                    *dst++ = val >> 16;
+                    *dst++ = val >>  8;
+                }
+                dst += ctx->cursor_stride - ctx->cursor_w * 4;
+            }
+        }
+        break;
+    default:
+        avpriv_request_sample(avctx, "Cursor format %08x", cursor_fmt);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    return 0;
+}
+
+/* Convert a single YUV pixel to RGB. */
+static inline void tdsc_yuv2rgb(uint8_t *out, int Y, int U, int V)
+{
+    out[0] = av_clip_uint8(Y + (             91881 * V + 32768 >> 16));
+    out[1] = av_clip_uint8(Y + (-22554 * U - 46802 * V + 32768 >> 16));
+    out[2] = av_clip_uint8(Y + (116130 * U             + 32768 >> 16));
+}
+
+/* Convert a YUV420 buffer to a RGB buffer. */
+static av_always_inline void tdsc_blit(uint8_t *dst, int dst_stride,
+                                       const uint8_t *srcy, int srcy_stride,
+                                       const uint8_t *srcu, const uint8_t *srcv,
+                                       int srcuv_stride, int width, int height)
+{
+    int col, line;
+    for (line = 0; line < height; line++) {
+        for (col = 0; col < width; col++)
+            tdsc_yuv2rgb(dst + col * 3, srcy[col],
+                         srcu[col >> 1] - 128, srcv[col >> 1] - 128);
+
+        dst  +=   dst_stride;
+        srcy +=  srcy_stride;
+        srcu += srcuv_stride * (line & 1);
+        srcv += srcuv_stride * (line & 1);
+    }
+}
+
+/* Invoke the MJPEG decoder to decode the tile. */
+static int tdsc_decode_jpeg_tile(AVCodecContext *avctx, int tile_size,
+                                 int x, int y, int w, int h)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    AVPacket jpkt;
+    int got_frame = 0;
+    int ret;
+
+    /* Prepare a packet and send to the MJPEG decoder */
+    av_init_packet(&jpkt);
+    jpkt.data = ctx->tilebuffer;
+    jpkt.size = tile_size;
+
+    ret = avcodec_decode_video2(ctx->jpeg_avctx, ctx->jpgframe,
+                                &got_frame, &jpkt);
+    if (ret < 0 || !got_frame || ctx->jpgframe->format != AV_PIX_FMT_YUVJ420P) {
+        av_log(avctx, AV_LOG_ERROR,
+               "JPEG decoding error (%d) for (%d) frame.\n",
+               ret, got_frame);
+
+        /* Normally skip, error if explode */
+        if (avctx->err_recognition & AV_EF_EXPLODE)
+            return AVERROR_INVALIDDATA;
+        else
+            return 0;
+    }
+
+    /* Let's paint ont the buffer */
+    tdsc_blit(ctx->refframe->data[0] + x * 3 + ctx->refframe->linesize[0] * y,
+              ctx->refframe->linesize[0],
+              ctx->jpgframe->data[0], ctx->jpgframe->linesize[0],
+              ctx->jpgframe->data[1], ctx->jpgframe->data[2],
+              ctx->jpgframe->linesize[1], w, h);
+
+    av_frame_unref(ctx->jpgframe);
+
+    return 0;
+}
+
+/* Parse frame and either copy data or decode JPEG. */
+static int tdsc_decode_tiles(AVCodecContext *avctx, int number_tiles)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    int i;
+
+    /* Iterate over the number of tiles */
+    for (i = 0; i < number_tiles; i++) {
+        int tile_size;
+        int tile_mode;
+        int x, y, w, h;
+        int ret;
+
+        if (bytestream2_get_bytes_left(&ctx->gbc) < 4 ||
+            bytestream2_get_le32(&ctx->gbc) != MKTAG('T','D','S','B') ||
+            bytestream2_get_bytes_left(&ctx->gbc) < TDSB_HEADER_SIZE - 4) {
+            av_log(avctx, AV_LOG_ERROR, "TDSB tag is too small.\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        tile_size = bytestream2_get_le32(&ctx->gbc);
+        if (bytestream2_get_bytes_left(&ctx->gbc) < tile_size)
+            return AVERROR_INVALIDDATA;
+
+        tile_mode = bytestream2_get_le32(&ctx->gbc);
+        bytestream2_skip(&ctx->gbc, 4); // unknown
+        x = bytestream2_get_le32(&ctx->gbc);
+        y = bytestream2_get_le32(&ctx->gbc);
+        w = bytestream2_get_le32(&ctx->gbc) - x;
+        h = bytestream2_get_le32(&ctx->gbc) - y;
+
+        if (x >= ctx->width || y >= ctx->height) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Invalid tile position (%d.%d outside %dx%d).\n",
+                   x, y, ctx->width, ctx->height);
+            return AVERROR_INVALIDDATA;
+        }
+        if (x + w > ctx->width || y + h > ctx->height) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Invalid tile size %dx%d\n", w, h);
+            return AVERROR_INVALIDDATA;
+        }
+
+        ret = av_reallocp(&ctx->tilebuffer, tile_size);
+        if (!ctx->tilebuffer)
+            return ret;
+
+        bytestream2_get_buffer(&ctx->gbc, ctx->tilebuffer, tile_size);
+
+        if (tile_mode == MKTAG('G','E','P','J')) {
+            /* Decode JPEG tile and copy it in the reference frame */
+            ret = tdsc_decode_jpeg_tile(avctx, tile_size, x, y, w, h);
+            if (ret < 0)
+                return ret;
+        } else if (tile_mode == MKTAG(' ','W','A','R')) {
+            /* Just copy the buffer to output */
+            av_image_copy_plane(ctx->refframe->data[0] + x * 3 +
+                                ctx->refframe->linesize[0] * y,
+                                ctx->refframe->linesize[0], ctx->tilebuffer,
+                                w * 3, w * 3, h);
+        } else {
+            av_log(avctx, AV_LOG_ERROR, "Unknown tile type %08x.\n", tile_mode);
+            return AVERROR_INVALIDDATA;
+        }
+        av_log(avctx, AV_LOG_DEBUG, "Tile %d, %dx%d (%d.%d)\n", i, w, h, x, y);
+    }
+
+    return 0;
+}
+
+static int tdsc_parse_tdsf(AVCodecContext *avctx, int number_tiles)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    int ret, w, h, init_refframe = !ctx->refframe->data[0];
+
+    /* BITMAPINFOHEADER
+     * http://msdn.microsoft.com/en-us/library/windows/desktop/dd183376.aspx */
+    if (bytestream2_get_le32(&ctx->gbc) != BITMAPINFOHEADER_SIZE)
+        return AVERROR_INVALIDDATA;
+
+    /* Store size, but wait for context reinit before updating avctx */
+    w =  bytestream2_get_le32(&ctx->gbc);
+    h = -bytestream2_get_le32(&ctx->gbc);
+
+    if (bytestream2_get_le16(&ctx->gbc) != 1 ||  // 1 plane
+        bytestream2_get_le16(&ctx->gbc) != 24)   // BGR24
+        return AVERROR_INVALIDDATA;
+
+    bytestream2_skip(&ctx->gbc, 24); // unused fields
+
+    /* Update sizes */
+    if (avctx->width != w || avctx->height != h) {
+        av_log(avctx, AV_LOG_DEBUG, "Size update %dx%d -> %d%d.\n",
+               avctx->width, avctx->height, ctx->width, ctx->height);
+        ret = ff_set_dimensions(avctx, w, h);
+        if (ret < 0)
+            return ret;
+        init_refframe = 1;
+    }
+    ctx->refframe->width  = ctx->width  = w;
+    ctx->refframe->height = ctx->height = h;
+
+    /* Allocate the reference frame if not already done or on size change */
+    if (init_refframe) {
+        ret = av_frame_get_buffer(ctx->refframe, 32);
+        if (ret < 0)
+            return ret;
+    }
+
+    /* Decode all tiles in a frame */
+    return tdsc_decode_tiles(avctx, number_tiles);
+}
+
+static int tdsc_parse_dtsm(AVCodecContext *avctx)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    int ret;
+    int action = bytestream2_get_le32(&ctx->gbc);
+
+    bytestream2_skip(&ctx->gbc, 4); // some kind of ID or version maybe?
+
+    if (action == 2 || action == 3) {
+        /* Load cursor coordinates */
+        ctx->cursor_x = bytestream2_get_le32(&ctx->gbc);
+        ctx->cursor_y = bytestream2_get_le32(&ctx->gbc);
+
+        /* Load a full cursor sprite */
+        if (action == 3) {
+            ret = tdsc_load_cursor(avctx);
+            /* Do not consider cursor errors fatal unless in explode mode */
+            if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
+                return ret;
+        }
+    } else {
+        avpriv_request_sample(avctx, "Cursor action %d", action);
+    }
+
+    return 0;
+}
+
+static int tdsc_decode_frame(AVCodecContext *avctx, void *data,
+                             int *got_frame, AVPacket *avpkt)
+{
+    TDSCContext *ctx = avctx->priv_data;
+    AVFrame *frame = data;
+    int ret, tag_header, keyframe = 0;
+    uLongf dlen;
+
+    /* Resize deflate buffer on resolution change */
+    if (ctx->width != avctx->width || ctx->height != avctx->height) {
+        ctx->deflatelen = avctx->width * avctx->height * (3 + 1);
+        ret = av_reallocp(&ctx->deflatebuffer, ctx->deflatelen);
+        if (ret < 0)
+            return ret;
+    }
+    dlen = ctx->deflatelen;
+
+    /* Frames are deflated, need to inflate them first */
+    ret = uncompress(ctx->deflatebuffer, &dlen, avpkt->data, avpkt->size);
+    if (ret) {
+        av_log(avctx, AV_LOG_ERROR, "Deflate error %d.\n", ret);
+        return AVERROR_UNKNOWN;
+    }
+
+    bytestream2_init(&ctx->gbc, ctx->deflatebuffer, dlen);
+
+    /* Check for tag and for size info */
+    if (bytestream2_get_bytes_left(&ctx->gbc) < 4 + 4) {
+        av_log(avctx, AV_LOG_ERROR, "Frame is too small.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* Read tag */
+    tag_header = bytestream2_get_le32(&ctx->gbc);
+
+    if (tag_header == MKTAG('T','D','S','F')) {
+        int number_tiles;
+        if (bytestream2_get_bytes_left(&ctx->gbc) < TDSF_HEADER_SIZE) {
+            av_log(avctx, AV_LOG_ERROR, "TDSF tag is too small.\n");
+            return AVERROR_INVALIDDATA;
+        }
+        /* First 4 bytes here are the number of GEPJ/WAR tiles in this frame */
+        number_tiles = bytestream2_get_le32(&ctx->gbc);
+
+        bytestream2_skip(&ctx->gbc, 4); // internal timestamp maybe?
+        keyframe = bytestream2_get_le32(&ctx->gbc) == 0x30;
+
+        ret = tdsc_parse_tdsf(avctx, number_tiles);
+        if (ret < 0)
+            return ret;
+
+        /* Check if there is anything else we are able to parse */
+        if (bytestream2_get_bytes_left(&ctx->gbc) >= 4 + 4)
+            tag_header = bytestream2_get_le32(&ctx->gbc);
+    }
+
+    /* This tag can be after a TDSF block or on its own frame */
+    if (tag_header == MKTAG('D','T','S','M')) {
+        /* First 4 bytes here are the total size in bytes for this frame */
+        int tag_size = bytestream2_get_le32(&ctx->gbc);
+
+        if (bytestream2_get_bytes_left(&ctx->gbc) < tag_size) {
+            av_log(avctx, AV_LOG_ERROR, "DTSM tag is too small.\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        ret = tdsc_parse_dtsm(avctx);
+        if (ret < 0)
+            return ret;
+    }
+
+    /* Get the output frame and copy the reference frame */
+    ret = ff_get_buffer(avctx, frame, 0);
+    if (ret < 0)
+        return ret;
+
+    ret = av_frame_copy(frame, ctx->refframe);
+    if (ret < 0)
+        return ret;
+
+    /* Paint the cursor on the output frame */
+    tdsc_paint_cursor(avctx, frame->data[0], frame->linesize[0]);
+
+    /* Frame is ready to be output */
+    if (keyframe) {
+        frame->pict_type = AV_PICTURE_TYPE_I;
+        frame->key_frame = 1;
+    } else {
+        frame->pict_type = AV_PICTURE_TYPE_P;
+    }
+    *got_frame = 1;
+
+    return 0;
+}
+
+AVCodec ff_tdsc_decoder = {
+    .name           = "tdsc",
+    .long_name      = NULL_IF_CONFIG_SMALL("TDSC"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_TDSC,
+    .init           = tdsc_init,
+    .decode         = tdsc_decode_frame,
+    .close          = tdsc_close,
+    .priv_data_size = sizeof(TDSCContext),
+    .capabilities   = CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
+                      FF_CODEC_CAP_INIT_CLEANUP,
+};