ffmpeg/libavcodec/rscc.c

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/*
* 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,
};