[deb_ffmpeg.git] / ffmpeg / libavcodec / cdgraphics.c

/*
 * CD Graphics Video Decoder
 * Copyright (c) 2009 Michael Tison
 *
 * 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 "avcodec.h"
#include "bytestream.h"
#include "internal.h"

/**
 * @file
 * @brief CD Graphics Video Decoder
 * @author Michael Tison
 * @see http://wiki.multimedia.cx/index.php?title=CD_Graphics
 * @see http://www.ccs.neu.edu/home/bchafy/cdb/info/cdg
 */

/// default screen sizes
#define CDG_FULL_WIDTH           300
#define CDG_FULL_HEIGHT          216
#define CDG_DISPLAY_WIDTH        294
#define CDG_DISPLAY_HEIGHT       204
#define CDG_BORDER_WIDTH           6
#define CDG_BORDER_HEIGHT         12

/// masks
#define CDG_COMMAND             0x09
#define CDG_MASK                0x3F

/// instruction codes
#define CDG_INST_MEMORY_PRESET     1
#define CDG_INST_BORDER_PRESET     2
#define CDG_INST_TILE_BLOCK        6
#define CDG_INST_SCROLL_PRESET    20
#define CDG_INST_SCROLL_COPY      24
#define CDG_INST_LOAD_PAL_LO      30
#define CDG_INST_LOAD_PAL_HIGH    31
#define CDG_INST_TILE_BLOCK_XOR   38

/// data sizes
#define CDG_PACKET_SIZE           24
#define CDG_DATA_SIZE             16
#define CDG_TILE_HEIGHT           12
#define CDG_TILE_WIDTH             6
#define CDG_MINIMUM_PKT_SIZE       6
#define CDG_MINIMUM_SCROLL_SIZE    3
#define CDG_HEADER_SIZE            8
#define CDG_PALETTE_SIZE          16

typedef struct CDGraphicsContext {
    AVFrame *frame;
    int hscroll;
    int vscroll;
} CDGraphicsContext;

static av_cold int cdg_decode_init(AVCodecContext *avctx)
{
    CDGraphicsContext *cc = avctx->priv_data;

    cc->frame = av_frame_alloc();
    if (!cc->frame)
        return AVERROR(ENOMEM);

    avctx->width   = CDG_FULL_WIDTH;
    avctx->height  = CDG_FULL_HEIGHT;
    avctx->pix_fmt = AV_PIX_FMT_PAL8;

    return 0;
}

static void cdg_border_preset(CDGraphicsContext *cc, uint8_t *data)
{
    int y;
    int lsize    = cc->frame->linesize[0];
    uint8_t *buf = cc->frame->data[0];
    int color    = data[0] & 0x0F;

    if (!(data[1] & 0x0F)) {
        /// fill the top and bottom borders
        memset(buf, color, CDG_BORDER_HEIGHT * lsize);
        memset(buf + (CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT) * lsize,
               color, CDG_BORDER_HEIGHT * lsize);

        /// fill the side borders
        for (y = CDG_BORDER_HEIGHT; y < CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT; y++) {
            memset(buf + y * lsize, color, CDG_BORDER_WIDTH);
            memset(buf + CDG_FULL_WIDTH - CDG_BORDER_WIDTH + y * lsize,
                   color, CDG_BORDER_WIDTH);
        }
    }
}

static void cdg_load_palette(CDGraphicsContext *cc, uint8_t *data, int low)
{
    uint8_t r, g, b;
    uint16_t color;
    int i;
    int array_offset  = low ? 0 : 8;
    uint32_t *palette = (uint32_t *) cc->frame->data[1];

    for (i = 0; i < 8; i++) {
        color = (data[2 * i] << 6) + (data[2 * i + 1] & 0x3F);
        r = ((color >> 8) & 0x000F) * 17;
        g = ((color >> 4) & 0x000F) * 17;
        b = ((color     ) & 0x000F) * 17;
        palette[i + array_offset] = 0xFFU << 24 | r << 16 | g << 8 | b;
    }
    cc->frame->palette_has_changed = 1;
}

static int cdg_tile_block(CDGraphicsContext *cc, uint8_t *data, int b)
{
    unsigned ci, ri;
    int color;
    int x, y;
    int ai;
    int stride   = cc->frame->linesize[0];
    uint8_t *buf = cc->frame->data[0];

    ri = (data[2] & 0x1F) * CDG_TILE_HEIGHT + cc->vscroll;
    ci = (data[3] & 0x3F) * CDG_TILE_WIDTH  + cc->hscroll;

    if (ri > (CDG_FULL_HEIGHT - CDG_TILE_HEIGHT))
        return AVERROR(EINVAL);
    if (ci > (CDG_FULL_WIDTH - CDG_TILE_WIDTH))
        return AVERROR(EINVAL);

    for (y = 0; y < CDG_TILE_HEIGHT; y++) {
        for (x = 0; x < CDG_TILE_WIDTH; x++) {
            if (!((data[4 + y] >> (5 - x)) & 0x01))
                color = data[0] & 0x0F;
            else
                color = data[1] & 0x0F;

            ai = ci + x + (stride * (ri + y));
            if (b)
                color ^= buf[ai];
            buf[ai] = color;
        }
    }

    return 0;
}

#define UP    2
#define DOWN  1
#define LEFT  2
#define RIGHT 1

static void cdg_copy_rect_buf(int out_tl_x, int out_tl_y, uint8_t *out,
                              int in_tl_x, int in_tl_y, uint8_t *in,
                              int w, int h, int stride)
{
    int y;

    in  += in_tl_x  + in_tl_y  * stride;
    out += out_tl_x + out_tl_y * stride;
    for (y = 0; y < h; y++)
        memcpy(out + y * stride, in + y * stride, w);
}

static void cdg_fill_rect_preset(int tl_x, int tl_y, uint8_t *out,
                                 int color, int w, int h, int stride)
{
    int y;

    for (y = tl_y; y < tl_y + h; y++)
        memset(out + tl_x + y * stride, color, w);
}

static void cdg_fill_wrapper(int out_tl_x, int out_tl_y, uint8_t *out,
                             int in_tl_x, int in_tl_y, uint8_t *in,
                             int color, int w, int h, int stride, int roll)
{
    if (roll) {
        cdg_copy_rect_buf(out_tl_x, out_tl_y, out, in_tl_x, in_tl_y,
                          in, w, h, stride);
    } else {
        cdg_fill_rect_preset(out_tl_x, out_tl_y, out, color, w, h, stride);
    }
}

static void cdg_scroll(CDGraphicsContext *cc, uint8_t *data,
                       AVFrame *new_frame, int roll_over)
{
    int color;
    int hscmd, h_off, hinc, vscmd, v_off, vinc;
    int y;
    int stride   = cc->frame->linesize[0];
    uint8_t *in  = cc->frame->data[0];
    uint8_t *out = new_frame->data[0];

    color =  data[0] & 0x0F;
    hscmd = (data[1] & 0x30) >> 4;
    vscmd = (data[2] & 0x30) >> 4;

    h_off =  FFMIN(data[1] & 0x07, CDG_BORDER_WIDTH  - 1);
    v_off =  FFMIN(data[2] & 0x0F, CDG_BORDER_HEIGHT - 1);

    /// find the difference and save the offset for cdg_tile_block usage
    hinc = h_off - cc->hscroll;
    vinc = v_off - cc->vscroll;
    cc->hscroll = h_off;
    cc->vscroll = v_off;

    if (vscmd == UP)
        vinc -= 12;
    if (vscmd == DOWN)
        vinc += 12;
    if (hscmd == LEFT)
        hinc -= 6;
    if (hscmd == RIGHT)
        hinc += 6;

    if (!hinc && !vinc)
        return;

    memcpy(new_frame->data[1], cc->frame->data[1], CDG_PALETTE_SIZE * 4);

    for (y = FFMAX(0, vinc); y < FFMIN(CDG_FULL_HEIGHT + vinc, CDG_FULL_HEIGHT); y++)
        memcpy(out + FFMAX(0, hinc) + stride * y,
               in + FFMAX(0, hinc) - hinc + (y - vinc) * stride,
               FFMIN(stride + hinc, stride));

    if (vinc > 0)
        cdg_fill_wrapper(0, 0, out,
                         0, CDG_FULL_HEIGHT - vinc, in, color,
                         stride, vinc, stride, roll_over);
    else if (vinc < 0)
        cdg_fill_wrapper(0, CDG_FULL_HEIGHT + vinc, out,
                         0, 0, in, color,
                         stride, -1 * vinc, stride, roll_over);

    if (hinc > 0)
        cdg_fill_wrapper(0, 0, out,
                         CDG_FULL_WIDTH - hinc, 0, in, color,
                         hinc, CDG_FULL_HEIGHT, stride, roll_over);
    else if (hinc < 0)
        cdg_fill_wrapper(CDG_FULL_WIDTH + hinc, 0, out,
                         0, 0, in, color,
                         -1 * hinc, CDG_FULL_HEIGHT, stride, roll_over);

}

static int cdg_decode_frame(AVCodecContext *avctx,
                            void *data, int *got_frame, AVPacket *avpkt)
{
    GetByteContext gb;
    int buf_size       = avpkt->size;
    int ret;
    uint8_t command, inst;
    uint8_t cdg_data[CDG_DATA_SIZE] = {0};
    AVFrame *frame = data;
    CDGraphicsContext *cc = avctx->priv_data;

    if (buf_size < CDG_MINIMUM_PKT_SIZE) {
        av_log(avctx, AV_LOG_ERROR, "buffer too small for decoder\n");
        return AVERROR(EINVAL);
    }
    if (buf_size > CDG_HEADER_SIZE + CDG_DATA_SIZE) {
        av_log(avctx, AV_LOG_ERROR, "buffer too big for decoder\n");
        return AVERROR(EINVAL);
    }

    bytestream2_init(&gb, avpkt->data, avpkt->size);

    if ((ret = ff_reget_buffer(avctx, cc->frame)) < 0)
        return ret;
    if (!avctx->frame_number) {
        memset(cc->frame->data[0], 0, cc->frame->linesize[0] * avctx->height);
        memset(cc->frame->data[1], 0, AVPALETTE_SIZE);
    }

    command = bytestream2_get_byte(&gb);
    inst    = bytestream2_get_byte(&gb);
    inst    &= CDG_MASK;
    bytestream2_skip(&gb, 2);
    bytestream2_get_buffer(&gb, cdg_data, sizeof(cdg_data));

    if ((command & CDG_MASK) == CDG_COMMAND) {
        switch (inst) {
        case CDG_INST_MEMORY_PRESET:
            if (!(cdg_data[1] & 0x0F))
                memset(cc->frame->data[0], cdg_data[0] & 0x0F,
                       cc->frame->linesize[0] * CDG_FULL_HEIGHT);
            break;
        case CDG_INST_LOAD_PAL_LO:
        case CDG_INST_LOAD_PAL_HIGH:
            if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) {
                av_log(avctx, AV_LOG_ERROR, "buffer too small for loading palette\n");
                return AVERROR(EINVAL);
            }

            cdg_load_palette(cc, cdg_data, inst == CDG_INST_LOAD_PAL_LO);
            break;
        case CDG_INST_BORDER_PRESET:
            cdg_border_preset(cc, cdg_data);
            break;
        case CDG_INST_TILE_BLOCK_XOR:
        case CDG_INST_TILE_BLOCK:
            if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) {
                av_log(avctx, AV_LOG_ERROR, "buffer too small for drawing tile\n");
                return AVERROR(EINVAL);
            }

            ret = cdg_tile_block(cc, cdg_data, inst == CDG_INST_TILE_BLOCK_XOR);
            if (ret) {
                av_log(avctx, AV_LOG_ERROR, "tile is out of range\n");
                return ret;
            }
            break;
        case CDG_INST_SCROLL_PRESET:
        case CDG_INST_SCROLL_COPY:
            if (buf_size - CDG_HEADER_SIZE < CDG_MINIMUM_SCROLL_SIZE) {
                av_log(avctx, AV_LOG_ERROR, "buffer too small for scrolling\n");
                return AVERROR(EINVAL);
            }

            if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
                return ret;

            cdg_scroll(cc, cdg_data, frame, inst == CDG_INST_SCROLL_COPY);
            av_frame_unref(cc->frame);
            ret = av_frame_ref(cc->frame, frame);
            if (ret < 0)
                return ret;
            break;
        default:
            break;
        }

        if (!frame->data[0]) {
            ret = av_frame_ref(frame, cc->frame);
            if (ret < 0)
                return ret;
        }
        *got_frame = 1;
    } else {
        *got_frame = 0;
    }

    return avpkt->size;
}

static av_cold int cdg_decode_end(AVCodecContext *avctx)
{
    CDGraphicsContext *cc = avctx->priv_data;

    av_frame_free(&cc->frame);

    return 0;
}

AVCodec ff_cdgraphics_decoder = {
    .name           = "cdgraphics",
    .long_name      = NULL_IF_CONFIG_SMALL("CD Graphics video"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_CDGRAPHICS,
    .priv_data_size = sizeof(CDGraphicsContext),
    .init           = cdg_decode_init,
    .close          = cdg_decode_end,
    .decode         = cdg_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* CD Graphics Video Decoder
	3	* Copyright (c) 2009 Michael Tison
	4	*
	5	* This file is part of FFmpeg.
	6	*
	7	* FFmpeg is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU Lesser General Public
	9	* License as published by the Free Software Foundation; either
	10	* version 2.1 of the License, or (at your option) any later version.
	11	*
	12	* FFmpeg is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* Lesser General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU Lesser General Public
	18	* License along with FFmpeg; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	20	*/
	21
	22	#include "avcodec.h"
	23	#include "bytestream.h"
	24	#include "internal.h"
	25
	26	/**
	27	* @file
	28	* @brief CD Graphics Video Decoder
	29	* @author Michael Tison
	30	* @see http://wiki.multimedia.cx/index.php?title=CD_Graphics
	31	* @see http://www.ccs.neu.edu/home/bchafy/cdb/info/cdg
	32	*/
	33
	34	/// default screen sizes
	35	#define CDG_FULL_WIDTH 300
	36	#define CDG_FULL_HEIGHT 216
	37	#define CDG_DISPLAY_WIDTH 294
	38	#define CDG_DISPLAY_HEIGHT 204
	39	#define CDG_BORDER_WIDTH 6
	40	#define CDG_BORDER_HEIGHT 12
	41
	42	/// masks
	43	#define CDG_COMMAND 0x09
	44	#define CDG_MASK 0x3F
	45
	46	/// instruction codes
	47	#define CDG_INST_MEMORY_PRESET 1
	48	#define CDG_INST_BORDER_PRESET 2
	49	#define CDG_INST_TILE_BLOCK 6
	50	#define CDG_INST_SCROLL_PRESET 20
	51	#define CDG_INST_SCROLL_COPY 24
	52	#define CDG_INST_LOAD_PAL_LO 30
	53	#define CDG_INST_LOAD_PAL_HIGH 31
	54	#define CDG_INST_TILE_BLOCK_XOR 38
	55
	56	/// data sizes
	57	#define CDG_PACKET_SIZE 24
	58	#define CDG_DATA_SIZE 16
	59	#define CDG_TILE_HEIGHT 12
	60	#define CDG_TILE_WIDTH 6
	61	#define CDG_MINIMUM_PKT_SIZE 6
	62	#define CDG_MINIMUM_SCROLL_SIZE 3
	63	#define CDG_HEADER_SIZE 8
	64	#define CDG_PALETTE_SIZE 16
65
66	typedef struct CDGraphicsContext {
67	AVFrame *frame;
68	int hscroll;
69	int vscroll;
70	} CDGraphicsContext;
71
72	static av_cold int cdg_decode_init(AVCodecContext *avctx)
73	{
74	CDGraphicsContext *cc = avctx->priv_data;
75
76	cc->frame = av_frame_alloc();
77	if (!cc->frame)
78	return AVERROR(ENOMEM);
79
80	avctx->width = CDG_FULL_WIDTH;
81	avctx->height = CDG_FULL_HEIGHT;
82	avctx->pix_fmt = AV_PIX_FMT_PAL8;
83
84	return 0;
85	}
86
87	static void cdg_border_preset(CDGraphicsContext cc, uint8_t data)
88	{
89	int y;
90	int lsize = cc->frame->linesize[0];
91	uint8_t *buf = cc->frame->data[0];
92	int color = data[0] & 0x0F;
93
94	if (!(data[1] & 0x0F)) {
95	/// fill the top and bottom borders
96	memset(buf, color, CDG_BORDER_HEIGHT * lsize);
97	memset(buf + (CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT) * lsize,
98	color, CDG_BORDER_HEIGHT * lsize);
99
100	/// fill the side borders
101	for (y = CDG_BORDER_HEIGHT; y < CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT; y++) {
102	memset(buf + y * lsize, color, CDG_BORDER_WIDTH);
103	memset(buf + CDG_FULL_WIDTH - CDG_BORDER_WIDTH + y * lsize,
104	color, CDG_BORDER_WIDTH);
105	}
106	}
107	}
108
109	static void cdg_load_palette(CDGraphicsContext cc, uint8_t data, int low)
110	{
111	uint8_t r, g, b;
112	uint16_t color;
113	int i;
114	int array_offset = low ? 0 : 8;
115	uint32_t palette = (uint32_t ) cc->frame->data[1];
116
117	for (i = 0; i < 8; i++) {
118	color = (data[2 * i] << 6) + (data[2 * i + 1] & 0x3F);
119	r = ((color >> 8) & 0x000F) * 17;
120	g = ((color >> 4) & 0x000F) * 17;
121	b = ((color ) & 0x000F) * 17;
122	palette[i + array_offset] = 0xFFU << 24 \| r << 16 \| g << 8 \| b;
123	}
124	cc->frame->palette_has_changed = 1;
125	}
126
127	static int cdg_tile_block(CDGraphicsContext cc, uint8_t data, int b)
128	{
129	unsigned ci, ri;
130	int color;
131	int x, y;
132	int ai;
133	int stride = cc->frame->linesize[0];
134	uint8_t *buf = cc->frame->data[0];
135
136	ri = (data[2] & 0x1F) * CDG_TILE_HEIGHT + cc->vscroll;
137	ci = (data[3] & 0x3F) * CDG_TILE_WIDTH + cc->hscroll;
138
139	if (ri > (CDG_FULL_HEIGHT - CDG_TILE_HEIGHT))
140	return AVERROR(EINVAL);
141	if (ci > (CDG_FULL_WIDTH - CDG_TILE_WIDTH))
142	return AVERROR(EINVAL);
143
144	for (y = 0; y < CDG_TILE_HEIGHT; y++) {
145	for (x = 0; x < CDG_TILE_WIDTH; x++) {
146	if (!((data[4 + y] >> (5 - x)) & 0x01))
147	color = data[0] & 0x0F;
148	else
149	color = data[1] & 0x0F;
150
151	ai = ci + x + (stride * (ri + y));
152	if (b)
153	color ^= buf[ai];
154	buf[ai] = color;
155	}
156	}
157
158	return 0;
159	}
160
161	#define UP 2
162	#define DOWN 1
163	#define LEFT 2
164	#define RIGHT 1
165
166	static void cdg_copy_rect_buf(int out_tl_x, int out_tl_y, uint8_t *out,
167	int in_tl_x, int in_tl_y, uint8_t *in,
168	int w, int h, int stride)
169	{
170	int y;
171
172	in += in_tl_x + in_tl_y * stride;
173	out += out_tl_x + out_tl_y * stride;
174	for (y = 0; y < h; y++)
175	memcpy(out + y * stride, in + y * stride, w);
176	}
177
178	static void cdg_fill_rect_preset(int tl_x, int tl_y, uint8_t *out,
179	int color, int w, int h, int stride)
180	{
181	int y;
182
183	for (y = tl_y; y < tl_y + h; y++)
184	memset(out + tl_x + y * stride, color, w);
185	}
186
187	static void cdg_fill_wrapper(int out_tl_x, int out_tl_y, uint8_t *out,
188	int in_tl_x, int in_tl_y, uint8_t *in,
189	int color, int w, int h, int stride, int roll)
190	{
191	if (roll) {
192	cdg_copy_rect_buf(out_tl_x, out_tl_y, out, in_tl_x, in_tl_y,
193	in, w, h, stride);
194	} else {
195	cdg_fill_rect_preset(out_tl_x, out_tl_y, out, color, w, h, stride);
196	}
197	}
198
199	static void cdg_scroll(CDGraphicsContext cc, uint8_t data,
200	AVFrame *new_frame, int roll_over)
201	{
202	int color;
203	int hscmd, h_off, hinc, vscmd, v_off, vinc;
204	int y;
205	int stride = cc->frame->linesize[0];
206	uint8_t *in = cc->frame->data[0];
207	uint8_t *out = new_frame->data[0];
208
209	color = data[0] & 0x0F;
210	hscmd = (data[1] & 0x30) >> 4;
211	vscmd = (data[2] & 0x30) >> 4;
212
213	h_off = FFMIN(data[1] & 0x07, CDG_BORDER_WIDTH - 1);
214	v_off = FFMIN(data[2] & 0x0F, CDG_BORDER_HEIGHT - 1);
215
216	/// find the difference and save the offset for cdg_tile_block usage
217	hinc = h_off - cc->hscroll;
218	vinc = v_off - cc->vscroll;
219	cc->hscroll = h_off;
220	cc->vscroll = v_off;
221
222	if (vscmd == UP)
223	vinc -= 12;
224	if (vscmd == DOWN)
225	vinc += 12;
226	if (hscmd == LEFT)
227	hinc -= 6;
228	if (hscmd == RIGHT)
229	hinc += 6;
230
231	if (!hinc && !vinc)
232	return;
233
234	memcpy(new_frame->data[1], cc->frame->data[1], CDG_PALETTE_SIZE * 4);
235
236	for (y = FFMAX(0, vinc); y < FFMIN(CDG_FULL_HEIGHT + vinc, CDG_FULL_HEIGHT); y++)
237	memcpy(out + FFMAX(0, hinc) + stride * y,
238	in + FFMAX(0, hinc) - hinc + (y - vinc) * stride,
239	FFMIN(stride + hinc, stride));
240
241	if (vinc > 0)
242	cdg_fill_wrapper(0, 0, out,
243	0, CDG_FULL_HEIGHT - vinc, in, color,
244	stride, vinc, stride, roll_over);
245	else if (vinc < 0)
246	cdg_fill_wrapper(0, CDG_FULL_HEIGHT + vinc, out,
247	0, 0, in, color,
248	stride, -1 * vinc, stride, roll_over);
249
250	if (hinc > 0)
251	cdg_fill_wrapper(0, 0, out,
252	CDG_FULL_WIDTH - hinc, 0, in, color,
253	hinc, CDG_FULL_HEIGHT, stride, roll_over);
254	else if (hinc < 0)
255	cdg_fill_wrapper(CDG_FULL_WIDTH + hinc, 0, out,
256	0, 0, in, color,
257	-1 * hinc, CDG_FULL_HEIGHT, stride, roll_over);
258
259	}
260
261	static int cdg_decode_frame(AVCodecContext *avctx,
262	void data, int got_frame, AVPacket *avpkt)
263	{
264	GetByteContext gb;
265	int buf_size = avpkt->size;
266	int ret;
267	uint8_t command, inst;
268	uint8_t cdg_data[CDG_DATA_SIZE] = {0};
269	AVFrame *frame = data;
270	CDGraphicsContext *cc = avctx->priv_data;
271
272	if (buf_size < CDG_MINIMUM_PKT_SIZE) {
273	av_log(avctx, AV_LOG_ERROR, "buffer too small for decoder\n");
274	return AVERROR(EINVAL);
275	}
276	if (buf_size > CDG_HEADER_SIZE + CDG_DATA_SIZE) {
277	av_log(avctx, AV_LOG_ERROR, "buffer too big for decoder\n");
278	return AVERROR(EINVAL);
279	}
280
281	bytestream2_init(&gb, avpkt->data, avpkt->size);
282
283	if ((ret = ff_reget_buffer(avctx, cc->frame)) < 0)
284	return ret;
285	if (!avctx->frame_number) {
286	memset(cc->frame->data[0], 0, cc->frame->linesize[0] * avctx->height);
287	memset(cc->frame->data[1], 0, AVPALETTE_SIZE);
288	}
289
290	command = bytestream2_get_byte(&gb);
291	inst = bytestream2_get_byte(&gb);
292	inst &= CDG_MASK;
293	bytestream2_skip(&gb, 2);
294	bytestream2_get_buffer(&gb, cdg_data, sizeof(cdg_data));
295
296	if ((command & CDG_MASK) == CDG_COMMAND) {
297	switch (inst) {
298	case CDG_INST_MEMORY_PRESET:
299	if (!(cdg_data[1] & 0x0F))
300	memset(cc->frame->data[0], cdg_data[0] & 0x0F,
301	cc->frame->linesize[0] * CDG_FULL_HEIGHT);
302	break;
303	case CDG_INST_LOAD_PAL_LO:
304	case CDG_INST_LOAD_PAL_HIGH:
305	if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) {
306	av_log(avctx, AV_LOG_ERROR, "buffer too small for loading palette\n");
307	return AVERROR(EINVAL);
308	}
309
310	cdg_load_palette(cc, cdg_data, inst == CDG_INST_LOAD_PAL_LO);
311	break;
312	case CDG_INST_BORDER_PRESET:
313	cdg_border_preset(cc, cdg_data);
314	break;
315	case CDG_INST_TILE_BLOCK_XOR:
316	case CDG_INST_TILE_BLOCK:
317	if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) {
318	av_log(avctx, AV_LOG_ERROR, "buffer too small for drawing tile\n");
319	return AVERROR(EINVAL);
320	}
321
322	ret = cdg_tile_block(cc, cdg_data, inst == CDG_INST_TILE_BLOCK_XOR);
323	if (ret) {
324	av_log(avctx, AV_LOG_ERROR, "tile is out of range\n");
325	return ret;
326	}
327	break;
328	case CDG_INST_SCROLL_PRESET:
329	case CDG_INST_SCROLL_COPY:
330	if (buf_size - CDG_HEADER_SIZE < CDG_MINIMUM_SCROLL_SIZE) {
331	av_log(avctx, AV_LOG_ERROR, "buffer too small for scrolling\n");
332	return AVERROR(EINVAL);
333	}
334
335	if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
336	return ret;
337
338	cdg_scroll(cc, cdg_data, frame, inst == CDG_INST_SCROLL_COPY);
339	av_frame_unref(cc->frame);
340	ret = av_frame_ref(cc->frame, frame);
341	if (ret < 0)
342	return ret;
343	break;
344	default:
345	break;
346	}
347
348	if (!frame->data[0]) {
349	ret = av_frame_ref(frame, cc->frame);
350	if (ret < 0)
351	return ret;
352	}
353	*got_frame = 1;
354	} else {
355	*got_frame = 0;
356	}
357
358	return avpkt->size;
359	}
360
361	static av_cold int cdg_decode_end(AVCodecContext *avctx)
362	{
363	CDGraphicsContext *cc = avctx->priv_data;
364
365	av_frame_free(&cc->frame);
366
367	return 0;
368	}
369
370	AVCodec ff_cdgraphics_decoder = {
371	.name = "cdgraphics",
372	.long_name = NULL_IF_CONFIG_SMALL("CD Graphics video"),
373	.type = AVMEDIA_TYPE_VIDEO,
374	.id = AV_CODEC_ID_CDGRAPHICS,
375	.priv_data_size = sizeof(CDGraphicsContext),
376	.init = cdg_decode_init,
377	.close = cdg_decode_end,
378	.decode = cdg_decode_frame,
379	.capabilities = CODEC_CAP_DR1,
380	};