[deb_ffmpeg.git] / ffmpeg / libavcodec / escape124.c

/*
 * Escape 124 Video Decoder
 * Copyright (C) 2008 Eli Friedman (eli.friedman@gmail.com)
 *
 * 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 "internal.h"

#define BITSTREAM_READER_LE
#include "get_bits.h"

typedef union MacroBlock {
    uint16_t pixels[4];
    uint32_t pixels32[2];
} MacroBlock;

typedef union SuperBlock {
    uint16_t pixels[64];
    uint32_t pixels32[32];
} SuperBlock;

typedef struct CodeBook {
    unsigned depth;
    unsigned size;
    MacroBlock* blocks;
} CodeBook;

typedef struct Escape124Context {
    AVFrame *frame;

    unsigned num_superblocks;

    CodeBook codebooks[3];
} Escape124Context;

/**
 * Initialize the decoder
 * @param avctx decoder context
 * @return 0 success, negative on error
 */
static av_cold int escape124_decode_init(AVCodecContext *avctx)
{
    Escape124Context *s = avctx->priv_data;

    avctx->pix_fmt = AV_PIX_FMT_RGB555;

    s->num_superblocks = ((unsigned)avctx->width / 8) *
                         ((unsigned)avctx->height / 8);

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

    return 0;
}

static av_cold int escape124_decode_close(AVCodecContext *avctx)
{
    unsigned i;
    Escape124Context *s = avctx->priv_data;

    for (i = 0; i < 3; i++)
        av_freep(&s->codebooks[i].blocks);

    av_frame_free(&s->frame);

    return 0;
}

static CodeBook unpack_codebook(GetBitContext* gb, unsigned depth,
                                 unsigned size)
{
    unsigned i, j;
    CodeBook cb = { 0 };

    if (size >= INT_MAX / 34 || get_bits_left(gb) < size * 34)
        return cb;

    if (size >= INT_MAX / sizeof(MacroBlock))
        return cb;
    cb.blocks = av_malloc(size ? size * sizeof(MacroBlock) : 1);
    if (!cb.blocks)
        return cb;

    cb.depth = depth;
    cb.size = size;
    for (i = 0; i < size; i++) {
        unsigned mask_bits = get_bits(gb, 4);
        unsigned color0 = get_bits(gb, 15);
        unsigned color1 = get_bits(gb, 15);

        for (j = 0; j < 4; j++) {
            if (mask_bits & (1 << j))
                cb.blocks[i].pixels[j] = color1;
            else
                cb.blocks[i].pixels[j] = color0;
        }
    }
    return cb;
}

static unsigned decode_skip_count(GetBitContext* gb)
{
    unsigned value;
    // This function reads a maximum of 23 bits,
    // which is within the padding space
    if (get_bits_left(gb) < 1)
        return -1;
    value = get_bits1(gb);
    if (!value)
        return value;

    value += get_bits(gb, 3);
    if (value != (1 + ((1 << 3) - 1)))
        return value;

    value += get_bits(gb, 7);
    if (value != (1 + ((1 << 3) - 1)) + ((1 << 7) - 1))
        return value;

    return value + get_bits(gb, 12);
}

static MacroBlock decode_macroblock(Escape124Context* s, GetBitContext* gb,
                                    int* codebook_index, int superblock_index)
{
    // This function reads a maximum of 22 bits; the callers
    // guard this function appropriately
    unsigned block_index, depth;
    int value = get_bits1(gb);
    if (value) {
        static const char transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
        value = get_bits1(gb);
        *codebook_index = transitions[*codebook_index][value];
    }

    depth = s->codebooks[*codebook_index].depth;

    // depth = 0 means that this shouldn't read any bits;
    // in theory, this is the same as get_bits(gb, 0), but
    // that doesn't actually work.
    block_index = depth ? get_bits(gb, depth) : 0;

    if (*codebook_index == 1) {
        block_index += superblock_index << s->codebooks[1].depth;
    }

    // This condition can occur with invalid bitstreams and
    // *codebook_index == 2
    if (block_index >= s->codebooks[*codebook_index].size)
        return (MacroBlock) { { 0 } };

    return s->codebooks[*codebook_index].blocks[block_index];
}

static void insert_mb_into_sb(SuperBlock* sb, MacroBlock mb, unsigned index) {
   // Formula: ((index / 4) * 16 + (index % 4) * 2) / 2
   uint32_t *dst = sb->pixels32 + index + (index & -4);

   // This technically violates C99 aliasing rules, but it should be safe.
   dst[0] = mb.pixels32[0];
   dst[4] = mb.pixels32[1];
}

static void copy_superblock(uint16_t* dest, unsigned dest_stride,
                            uint16_t* src, unsigned src_stride)
{
    unsigned y;
    if (src)
        for (y = 0; y < 8; y++)
            memcpy(dest + y * dest_stride, src + y * src_stride,
                   sizeof(uint16_t) * 8);
    else
        for (y = 0; y < 8; y++)
            memset(dest + y * dest_stride, 0, sizeof(uint16_t) * 8);
}

static const uint16_t mask_matrix[] = {0x1,   0x2,   0x10,   0x20,
                                       0x4,   0x8,   0x40,   0x80,
                                       0x100, 0x200, 0x1000, 0x2000,
                                       0x400, 0x800, 0x4000, 0x8000};

static int escape124_decode_frame(AVCodecContext *avctx,
                                  void *data, int *got_frame,
                                  AVPacket *avpkt)
{
    int buf_size = avpkt->size;
    Escape124Context *s = avctx->priv_data;
    AVFrame *frame = data;

    GetBitContext gb;
    unsigned frame_flags, frame_size;
    unsigned i;

    unsigned superblock_index, cb_index = 1,
             superblock_col_index = 0,
             superblocks_per_row = avctx->width / 8, skip = -1;

    uint16_t* old_frame_data, *new_frame_data;
    unsigned old_stride, new_stride;

    int ret;

    if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
        return ret;

    // This call also guards the potential depth reads for the
    // codebook unpacking.
    if (get_bits_left(&gb) < 64)
        return -1;

    frame_flags = get_bits_long(&gb, 32);
    frame_size  = get_bits_long(&gb, 32);

    // Leave last frame unchanged
    // FIXME: Is this necessary?  I haven't seen it in any real samples
    if (!(frame_flags & 0x114) || !(frame_flags & 0x7800000)) {
        if (!s->frame->data[0])
            return AVERROR_INVALIDDATA;

        av_log(avctx, AV_LOG_DEBUG, "Skipping frame\n");

        *got_frame = 1;
        if ((ret = av_frame_ref(frame, s->frame)) < 0)
            return ret;

        return frame_size;
    }

    for (i = 0; i < 3; i++) {
        if (frame_flags & (1 << (17 + i))) {
            unsigned cb_depth, cb_size;
            if (i == 2) {
                // This codebook can be cut off at places other than
                // powers of 2, leaving some of the entries undefined.
                cb_size = get_bits_long(&gb, 20);
                cb_depth = av_log2(cb_size - 1) + 1;
            } else {
                cb_depth = get_bits(&gb, 4);
                if (i == 0) {
                    // This is the most basic codebook: pow(2,depth) entries
                    // for a depth-length key
                    cb_size = 1 << cb_depth;
                } else {
                    // This codebook varies per superblock
                    // FIXME: I don't think this handles integer overflow
                    // properly
                    cb_size = s->num_superblocks << cb_depth;
                }
            }
            av_freep(&s->codebooks[i].blocks);
            s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size);
            if (!s->codebooks[i].blocks)
                return -1;
        }
    }

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

    new_frame_data = (uint16_t*)frame->data[0];
    new_stride = frame->linesize[0] / 2;
    old_frame_data = (uint16_t*)s->frame->data[0];
    old_stride = s->frame->linesize[0] / 2;

    for (superblock_index = 0; superblock_index < s->num_superblocks;
         superblock_index++) {
        MacroBlock mb;
        SuperBlock sb;
        unsigned multi_mask = 0;

        if (skip == -1) {
            // Note that this call will make us skip the rest of the blocks
            // if the frame prematurely ends
            skip = decode_skip_count(&gb);
        }

        if (skip) {
            copy_superblock(new_frame_data, new_stride,
                            old_frame_data, old_stride);
        } else {
            copy_superblock(sb.pixels, 8,
                            old_frame_data, old_stride);

            while (get_bits_left(&gb) >= 1 && !get_bits1(&gb)) {
                unsigned mask;
                mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
                mask = get_bits(&gb, 16);
                multi_mask |= mask;
                for (i = 0; i < 16; i++) {
                    if (mask & mask_matrix[i]) {
                        insert_mb_into_sb(&sb, mb, i);
                    }
                }
            }

            if (!get_bits1(&gb)) {
                unsigned inv_mask = get_bits(&gb, 4);
                for (i = 0; i < 4; i++) {
                    if (inv_mask & (1 << i)) {
                        multi_mask ^= 0xF << i*4;
                    } else {
                        multi_mask ^= get_bits(&gb, 4) << i*4;
                    }
                }

                for (i = 0; i < 16; i++) {
                    if (multi_mask & mask_matrix[i]) {
                        mb = decode_macroblock(s, &gb, &cb_index,
                                               superblock_index);
                        insert_mb_into_sb(&sb, mb, i);
                    }
                }
            } else if (frame_flags & (1 << 16)) {
                while (get_bits_left(&gb) >= 1 && !get_bits1(&gb)) {
                    mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
                    insert_mb_into_sb(&sb, mb, get_bits(&gb, 4));
                }
            }

            copy_superblock(new_frame_data, new_stride, sb.pixels, 8);
        }

        superblock_col_index++;
        new_frame_data += 8;
        if (old_frame_data)
            old_frame_data += 8;
        if (superblock_col_index == superblocks_per_row) {
            new_frame_data += new_stride * 8 - superblocks_per_row * 8;
            if (old_frame_data)
                old_frame_data += old_stride * 8 - superblocks_per_row * 8;
            superblock_col_index = 0;
        }
        skip--;
    }

    av_log(avctx, AV_LOG_DEBUG,
           "Escape sizes: %i, %i, %i\n",
           frame_size, buf_size, get_bits_count(&gb) / 8);

    av_frame_unref(s->frame);
    if ((ret = av_frame_ref(s->frame, frame)) < 0)
        return ret;

    *got_frame = 1;

    return frame_size;
}


AVCodec ff_escape124_decoder = {
    .name           = "escape124",
    .long_name      = NULL_IF_CONFIG_SMALL("Escape 124"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_ESCAPE124,
    .priv_data_size = sizeof(Escape124Context),
    .init           = escape124_decode_init,
    .close          = escape124_decode_close,
    .decode         = escape124_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* Escape 124 Video Decoder
	3	* Copyright (C) 2008 Eli Friedman (eli.friedman@gmail.com)
	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 "internal.h"
	24
	25	#define BITSTREAM_READER_LE
	26	#include "get_bits.h"
	27
	28	typedef union MacroBlock {
	29	uint16_t pixels[4];
	30	uint32_t pixels32[2];
	31	} MacroBlock;
	32
	33	typedef union SuperBlock {
	34	uint16_t pixels[64];
	35	uint32_t pixels32[32];
	36	} SuperBlock;
	37
	38	typedef struct CodeBook {
	39	unsigned depth;
	40	unsigned size;
	41	MacroBlock* blocks;
	42	} CodeBook;
	43
	44	typedef struct Escape124Context {
	45	AVFrame *frame;
	46
	47	unsigned num_superblocks;
	48
	49	CodeBook codebooks[3];
	50	} Escape124Context;
	51
	52	/**
	53	* Initialize the decoder
	54	* @param avctx decoder context
	55	* @return 0 success, negative on error
	56	*/
	57	static av_cold int escape124_decode_init(AVCodecContext *avctx)
	58	{
	59	Escape124Context *s = avctx->priv_data;
	60
	61	avctx->pix_fmt = AV_PIX_FMT_RGB555;
	62
	63	s->num_superblocks = ((unsigned)avctx->width / 8) *
	64	((unsigned)avctx->height / 8);
65
66	s->frame = av_frame_alloc();
67	if (!s->frame)
68	return AVERROR(ENOMEM);
69
70	return 0;
71	}
72
73	static av_cold int escape124_decode_close(AVCodecContext *avctx)
74	{
75	unsigned i;
76	Escape124Context *s = avctx->priv_data;
77
78	for (i = 0; i < 3; i++)
f6fa7814	79	av_freep(&s->codebooks[i].blocks);
2ba45a60 DM	80
	81	av_frame_free(&s->frame);
	82
	83	return 0;
	84	}
	85
	86	static CodeBook unpack_codebook(GetBitContext* gb, unsigned depth,
	87	unsigned size)
	88	{
	89	unsigned i, j;
	90	CodeBook cb = { 0 };
	91
	92	if (size >= INT_MAX / 34 \|\| get_bits_left(gb) < size * 34)
	93	return cb;
	94
	95	if (size >= INT_MAX / sizeof(MacroBlock))
	96	return cb;
	97	cb.blocks = av_malloc(size ? size * sizeof(MacroBlock) : 1);
	98	if (!cb.blocks)
	99	return cb;
	100
	101	cb.depth = depth;
	102	cb.size = size;
	103	for (i = 0; i < size; i++) {
	104	unsigned mask_bits = get_bits(gb, 4);
	105	unsigned color0 = get_bits(gb, 15);
	106	unsigned color1 = get_bits(gb, 15);
	107
	108	for (j = 0; j < 4; j++) {
	109	if (mask_bits & (1 << j))
	110	cb.blocks[i].pixels[j] = color1;
	111	else
	112	cb.blocks[i].pixels[j] = color0;
	113	}
	114	}
	115	return cb;
	116	}
	117
	118	static unsigned decode_skip_count(GetBitContext* gb)
	119	{
	120	unsigned value;
	121	// This function reads a maximum of 23 bits,
	122	// which is within the padding space
	123	if (get_bits_left(gb) < 1)
	124	return -1;
	125	value = get_bits1(gb);
	126	if (!value)
	127	return value;
	128
	129	value += get_bits(gb, 3);
	130	if (value != (1 + ((1 << 3) - 1)))
	131	return value;
	132
	133	value += get_bits(gb, 7);
	134	if (value != (1 + ((1 << 3) - 1)) + ((1 << 7) - 1))
	135	return value;
	136
	137	return value + get_bits(gb, 12);
	138	}
	139
	140	static MacroBlock decode_macroblock(Escape124Context* s, GetBitContext* gb,
	141	int* codebook_index, int superblock_index)
	142	{
	143	// This function reads a maximum of 22 bits; the callers
144	// guard this function appropriately
145	unsigned block_index, depth;
f6fa7814 DM	146	int value = get_bits1(gb);
f6fa7814 DM	147	if (value) {
2ba45a60	148	static const char transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
f6fa7814 DM	149	value = get_bits1(gb);
f6fa7814 DM	150	codebook_index = transitions[codebook_index][value];
2ba45a60 DM	151	}
	152
	153	depth = s->codebooks[*codebook_index].depth;
	154
	155	// depth = 0 means that this shouldn't read any bits;
	156	// in theory, this is the same as get_bits(gb, 0), but
	157	// that doesn't actually work.
	158	block_index = depth ? get_bits(gb, depth) : 0;
	159
	160	if (*codebook_index == 1) {
	161	block_index += superblock_index << s->codebooks[1].depth;
	162	}
	163
	164	// This condition can occur with invalid bitstreams and
	165	// *codebook_index == 2
	166	if (block_index >= s->codebooks[*codebook_index].size)
	167	return (MacroBlock) { { 0 } };
	168
	169	return s->codebooks[*codebook_index].blocks[block_index];
	170	}
	171
	172	static void insert_mb_into_sb(SuperBlock* sb, MacroBlock mb, unsigned index) {
	173	// Formula: ((index / 4) * 16 + (index % 4) * 2) / 2
	174	uint32_t *dst = sb->pixels32 + index + (index & -4);
	175
	176	// This technically violates C99 aliasing rules, but it should be safe.
	177	dst[0] = mb.pixels32[0];
	178	dst[4] = mb.pixels32[1];
	179	}
	180
	181	static void copy_superblock(uint16_t* dest, unsigned dest_stride,
	182	uint16_t* src, unsigned src_stride)
	183	{
	184	unsigned y;
	185	if (src)
	186	for (y = 0; y < 8; y++)
	187	memcpy(dest + y * dest_stride, src + y * src_stride,
	188	sizeof(uint16_t) * 8);
	189	else
	190	for (y = 0; y < 8; y++)
	191	memset(dest + y * dest_stride, 0, sizeof(uint16_t) * 8);
	192	}
	193
	194	static const uint16_t mask_matrix[] = {0x1, 0x2, 0x10, 0x20,
	195	0x4, 0x8, 0x40, 0x80,
	196	0x100, 0x200, 0x1000, 0x2000,
	197	0x400, 0x800, 0x4000, 0x8000};
	198
	199	static int escape124_decode_frame(AVCodecContext *avctx,
	200	void data, int got_frame,
	201	AVPacket *avpkt)
	202	{
	203	int buf_size = avpkt->size;
	204	Escape124Context *s = avctx->priv_data;
	205	AVFrame *frame = data;
	206
	207	GetBitContext gb;
	208	unsigned frame_flags, frame_size;
	209	unsigned i;
	210
	211	unsigned superblock_index, cb_index = 1,
	212	superblock_col_index = 0,
	213	superblocks_per_row = avctx->width / 8, skip = -1;
	214
215	uint16_t* old_frame_data, *new_frame_data;
216	unsigned old_stride, new_stride;
217
218	int ret;
219
220	if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
221	return ret;
222
223	// This call also guards the potential depth reads for the
224	// codebook unpacking.
225	if (get_bits_left(&gb) < 64)
226	return -1;
227
228	frame_flags = get_bits_long(&gb, 32);
229	frame_size = get_bits_long(&gb, 32);
230
231	// Leave last frame unchanged
232	// FIXME: Is this necessary? I haven't seen it in any real samples
233	if (!(frame_flags & 0x114) \|\| !(frame_flags & 0x7800000)) {
234	if (!s->frame->data[0])
235	return AVERROR_INVALIDDATA;
236
237	av_log(avctx, AV_LOG_DEBUG, "Skipping frame\n");
238
239	*got_frame = 1;
240	if ((ret = av_frame_ref(frame, s->frame)) < 0)
241	return ret;
242
243	return frame_size;
244	}
245
246	for (i = 0; i < 3; i++) {
247	if (frame_flags & (1 << (17 + i))) {
248	unsigned cb_depth, cb_size;
249	if (i == 2) {
250	// This codebook can be cut off at places other than
251	// powers of 2, leaving some of the entries undefined.
252	cb_size = get_bits_long(&gb, 20);
253	cb_depth = av_log2(cb_size - 1) + 1;
254	} else {
255	cb_depth = get_bits(&gb, 4);
256	if (i == 0) {
257	// This is the most basic codebook: pow(2,depth) entries
258	// for a depth-length key
259	cb_size = 1 << cb_depth;
260	} else {
261	// This codebook varies per superblock
262	// FIXME: I don't think this handles integer overflow
263	// properly
264	cb_size = s->num_superblocks << cb_depth;
265	}
266	}
f6fa7814	267	av_freep(&s->codebooks[i].blocks);
2ba45a60 DM	268	s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size);
	269	if (!s->codebooks[i].blocks)
	270	return -1;
	271	}
	272	}
	273
	274	if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
	275	return ret;
	276
	277	new_frame_data = (uint16_t*)frame->data[0];
	278	new_stride = frame->linesize[0] / 2;
	279	old_frame_data = (uint16_t*)s->frame->data[0];
	280	old_stride = s->frame->linesize[0] / 2;
	281
	282	for (superblock_index = 0; superblock_index < s->num_superblocks;
	283	superblock_index++) {
	284	MacroBlock mb;
	285	SuperBlock sb;
	286	unsigned multi_mask = 0;
	287
	288	if (skip == -1) {
	289	// Note that this call will make us skip the rest of the blocks
	290	// if the frame prematurely ends
	291	skip = decode_skip_count(&gb);
	292	}
	293
	294	if (skip) {
	295	copy_superblock(new_frame_data, new_stride,
	296	old_frame_data, old_stride);
	297	} else {
	298	copy_superblock(sb.pixels, 8,
	299	old_frame_data, old_stride);
	300
	301	while (get_bits_left(&gb) >= 1 && !get_bits1(&gb)) {
	302	unsigned mask;
	303	mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
	304	mask = get_bits(&gb, 16);
	305	multi_mask \|= mask;
	306	for (i = 0; i < 16; i++) {
	307	if (mask & mask_matrix[i]) {
	308	insert_mb_into_sb(&sb, mb, i);
	309	}
	310	}
	311	}
	312
	313	if (!get_bits1(&gb)) {
	314	unsigned inv_mask = get_bits(&gb, 4);
	315	for (i = 0; i < 4; i++) {
	316	if (inv_mask & (1 << i)) {
	317	multi_mask ^= 0xF << i*4;
	318	} else {
	319	multi_mask ^= get_bits(&gb, 4) << i*4;
	320	}
	321	}
	322
	323	for (i = 0; i < 16; i++) {
	324	if (multi_mask & mask_matrix[i]) {
	325	mb = decode_macroblock(s, &gb, &cb_index,
	326	superblock_index);
	327	insert_mb_into_sb(&sb, mb, i);
	328	}
	329	}
	330	} else if (frame_flags & (1 << 16)) {
	331	while (get_bits_left(&gb) >= 1 && !get_bits1(&gb)) {
332	mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
333	insert_mb_into_sb(&sb, mb, get_bits(&gb, 4));
334	}
335	}
336
337	copy_superblock(new_frame_data, new_stride, sb.pixels, 8);
338	}
339
340	superblock_col_index++;
341	new_frame_data += 8;
342	if (old_frame_data)
343	old_frame_data += 8;
344	if (superblock_col_index == superblocks_per_row) {
345	new_frame_data += new_stride * 8 - superblocks_per_row * 8;
346	if (old_frame_data)
347	old_frame_data += old_stride * 8 - superblocks_per_row * 8;
348	superblock_col_index = 0;
349	}
350	skip--;
351	}
352
353	av_log(avctx, AV_LOG_DEBUG,
354	"Escape sizes: %i, %i, %i\n",
355	frame_size, buf_size, get_bits_count(&gb) / 8);
356
357	av_frame_unref(s->frame);
358	if ((ret = av_frame_ref(s->frame, frame)) < 0)
359	return ret;
360
361	*got_frame = 1;
362
363	return frame_size;
364	}
365
366
367	AVCodec ff_escape124_decoder = {
368	.name = "escape124",
369	.long_name = NULL_IF_CONFIG_SMALL("Escape 124"),
370	.type = AVMEDIA_TYPE_VIDEO,
371	.id = AV_CODEC_ID_ESCAPE124,
372	.priv_data_size = sizeof(Escape124Context),
373	.init = escape124_decode_init,
374	.close = escape124_decode_close,
375	.decode = escape124_decode_frame,
376	.capabilities = CODEC_CAP_DR1,
377	};