innoHeim/Rsupport Screen Capture Codec decoder

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

1 files changed, 284 insertions, 0 deletions

diff --git a/libavcodec/rscc.c b/libavcodec/rscc.c
new file mode 100644
index 0000000000..c54482f949
--- /dev/null
+++ b/libavcodec/rscc.c
@@ -0,0 +1,284 @@
+/*
+ * innoHeim/Rsupport Screen Capture Codec
+ * 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
+ * innoHeim/Rsupport Screen Capture Codec decoder
+ *
+ * Fourcc: ISCC, RSCC
+ *
+ * Lossless codec, data stored in tiles, with optional deflate compression.
+ *
+ * Header contains the number of tiles in a frame with the tile coordinates,
+ * and it can be deflated or not. Similarly, pixel data comes after the header
+ * and a variable size value, and it can be deflated or just raw.
+ *
+ * Supports: BGRA
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <zlib.h>
+
+#include "libavutil/imgutils.h"
+#include "libavutil/internal.h"
+
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+#define TILE_SIZE 8
+
+typedef struct Tile {
+    int x, y;
+    int w, h;
+} Tile;
+
+typedef struct RsccContext {
+    GetByteContext gbc;
+    AVFrame *reference;
+    Tile *tiles;
+    unsigned int tiles_size;
+
+    /* zlib interaction */
+    uint8_t *inflated_buf;
+    uLongf inflated_size;
+} RsccContext;
+
+static av_cold int rscc_init(AVCodecContext *avctx)
+{
+    RsccContext *ctx = avctx->priv_data;
+
+    /* These needs to be set to estimate uncompressed buffer */
+    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;
+    }
+
+    /* Allocate reference frame */
+    ctx->reference = av_frame_alloc();
+    if (!ctx->reference)
+        return AVERROR(ENOMEM);
+
+    avctx->pix_fmt = AV_PIX_FMT_BGRA;
+
+    /* Store the value to check for keyframes */
+    ctx->inflated_size = avctx->width * avctx->height * 4;
+
+    /* Allocate maximum size possible, a full frame */
+    ctx->inflated_buf = av_malloc(ctx->inflated_size);
+    if (!ctx->inflated_buf)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static av_cold int rscc_close(AVCodecContext *avctx)
+{
+    RsccContext *ctx = avctx->priv_data;
+
+    av_freep(&ctx->tiles);
+    av_freep(&ctx->inflated_buf);
+    av_frame_free(&ctx->reference);
+
+    return 0;
+}
+
+static int rscc_decode_frame(AVCodecContext *avctx, void *data,
+                                     int *got_frame, AVPacket *avpkt)
+{
+    RsccContext *ctx = avctx->priv_data;
+    GetByteContext *gbc = &ctx->gbc;
+    GetByteContext tiles_gbc;
+    AVFrame *frame = data;
+    const uint8_t *pixels, *raw;
+    uint8_t *inflated_tiles = NULL;
+    int tiles_nb, packed_size, pixel_size = 0;
+    int i, ret = 0;
+
+    bytestream2_init(gbc, avpkt->data, avpkt->size);
+
+    /* Size check */
+    if (bytestream2_get_bytes_left(gbc) < 12) {
+        av_log(avctx, AV_LOG_ERROR, "Packet too small (%d)\n", avpkt->size);
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* Read number of tiles, and allocate the array */
+    tiles_nb = bytestream2_get_le16(gbc);
+    av_fast_malloc(&ctx->tiles, &ctx->tiles_size,
+                   tiles_nb * sizeof(*ctx->tiles));
+    if (!ctx->tiles) {
+        ret = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    av_log(avctx, AV_LOG_DEBUG, "Frame with %d tiles.\n", tiles_nb);
+
+    /* When there are more than 5 tiles, they are packed together with
+     * a size header. When that size does not match the number of tiles
+     * times the tile size, it means it needs to be inflated as well */
+    if (tiles_nb > 5) {
+        uLongf packed_tiles_size;
+
+        if (tiles_nb < 32)
+            packed_tiles_size = bytestream2_get_byte(gbc);
+        else
+            packed_tiles_size = bytestream2_get_le16(gbc);
+
+        ff_dlog(avctx, "packed tiles of size %lu.\n", packed_tiles_size);
+
+        /* If necessary, uncompress tiles, and hijack the bytestream reader */
+        if (packed_tiles_size != tiles_nb * TILE_SIZE) {
+            uLongf length = tiles_nb * TILE_SIZE;
+            inflated_tiles = av_malloc(length);
+            if (!inflated_tiles) {
+                ret = AVERROR(ENOMEM);
+                goto end;
+            }
+
+            ret = uncompress(inflated_tiles, &length,
+                             gbc->buffer, packed_tiles_size);
+            if (ret) {
+                av_log(avctx, AV_LOG_ERROR, "Tile deflate error %d.\n", ret);
+                ret = AVERROR_UNKNOWN;
+                goto end;
+            }
+
+            /* Skip the compressed tile section in the main byte reader,
+             * and point it to read the newly uncompressed data */
+            bytestream2_skip(gbc, packed_tiles_size);
+            bytestream2_init(&tiles_gbc, inflated_tiles, length);
+            gbc = &tiles_gbc;
+        }
+    }
+
+    /* Fill in array of tiles, keeping track of how many pixels are updated */
+    for (i = 0; i < tiles_nb; i++) {
+        ctx->tiles[i].x = bytestream2_get_le16(gbc);
+        ctx->tiles[i].w = bytestream2_get_le16(gbc);
+        ctx->tiles[i].y = bytestream2_get_le16(gbc);
+        ctx->tiles[i].h = bytestream2_get_le16(gbc);
+
+        pixel_size += ctx->tiles[i].w * ctx->tiles[i].h * 4;
+
+        ff_dlog(avctx, "tile %d orig(%d,%d) %dx%d.\n", i,
+                ctx->tiles[i].x, ctx->tiles[i].y,
+                ctx->tiles[i].w, ctx->tiles[i].h);
+
+        if (ctx->tiles[i].w == 0 || ctx->tiles[i].h == 0) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "invalid tile %d at (%d.%d) with size %dx%d.\n", i,
+                   ctx->tiles[i].x, ctx->tiles[i].y,
+                   ctx->tiles[i].w, ctx->tiles[i].h);
+            ret = AVERROR_INVALIDDATA;
+            goto end;
+        } else if (ctx->tiles[i].x + ctx->tiles[i].w > avctx->width ||
+                   ctx->tiles[i].y + ctx->tiles[i].h > avctx->height) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "out of bounds tile %d at (%d.%d) with size %dx%d.\n", i,
+                   ctx->tiles[i].x, ctx->tiles[i].y,
+                   ctx->tiles[i].w, ctx->tiles[i].h);
+            ret = AVERROR_INVALIDDATA;
+            goto end;
+        }
+    }
+
+    /* Reset the reader in case it had been modified before */
+    gbc = &ctx->gbc;
+
+    /* Extract how much pixel data the tiles contain */
+    if (pixel_size < 0x100)
+        packed_size = bytestream2_get_byte(gbc);
+    else if (pixel_size < 0x10000)
+        packed_size = bytestream2_get_le16(gbc);
+    else if (pixel_size < 0x1000000)
+        packed_size = bytestream2_get_le24(gbc);
+    else
+        packed_size = bytestream2_get_le32(gbc);
+
+    ff_dlog(avctx, "pixel_size %d packed_size %d.\n", pixel_size, packed_size);
+
+    /* Get pixels buffer, it may be deflated or just raw */
+    if (pixel_size == packed_size) {
+        pixels = gbc->buffer;
+    } else {
+        uLongf len = ctx->inflated_size;
+        ret = uncompress(ctx->inflated_buf, &len, gbc->buffer, packed_size);
+        if (ret) {
+            av_log(avctx, AV_LOG_ERROR, "Pixel deflate error %d.\n", ret);
+            ret = AVERROR_UNKNOWN;
+            goto end;
+        }
+        pixels = ctx->inflated_buf;
+    }
+
+    /* Allocate when needed */
+    ret = ff_reget_buffer(avctx, ctx->reference);
+    if (ret < 0)
+        goto end;
+
+    /* Pointer to actual pixels, will be updated when data is consumed */
+    raw = pixels;
+    for (i = 0; i < tiles_nb; i++) {
+        uint8_t *dst = ctx->reference->data[0] + ctx->reference->linesize[0] *
+                       (avctx->height - ctx->tiles[i].y - 1) +
+                       ctx->tiles[i].x * 4;
+        av_image_copy_plane(dst, -1 * ctx->reference->linesize[0],
+                            raw, ctx->tiles[i].w * 4,
+                            ctx->tiles[i].w * 4, ctx->tiles[i].h);
+        raw += ctx->tiles[i].w * 4 * ctx->tiles[i].h;
+    }
+
+    /* Frame is ready to be output */
+    ret = av_frame_ref(frame, ctx->reference);
+    if (ret < 0)
+        goto end;
+
+    /* Keyframe when the number of pixels updated matches the whole surface */
+    if (pixel_size == ctx->inflated_size) {
+        frame->pict_type = AV_PICTURE_TYPE_I;
+        frame->key_frame = 1;
+    } else {
+        frame->pict_type = AV_PICTURE_TYPE_P;
+    }
+    *got_frame = 1;
+
+end:
+    av_free(inflated_tiles);
+    return ret;
+}
+
+AVCodec ff_rscc_decoder = {
+    .name           = "rscc",
+    .long_name      = NULL_IF_CONFIG_SMALL("innoHeim/Rsupport Screen Capture Codec"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_RSCC,
+    .init           = rscc_init,
+    .decode         = rscc_decode_frame,
+    .close          = rscc_close,
+    .priv_data_size = sizeof(RsccContext),
+    .capabilities   = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
+                      FF_CODEC_CAP_INIT_CLEANUP,
+};