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/* |
* QPEG codec |
* Copyright (c) 2004 Konstantin Shishkov |
* |
* 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 |
*/ |
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/** |
* @file |
* QPEG codec. |
*/ |
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#include "avcodec.h" |
#include "bytestream.h" |
#include "internal.h" |
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typedef struct QpegContext{ |
AVCodecContext *avctx; |
AVFrame pic, ref; |
uint32_t pal[256]; |
GetByteContext buffer; |
} QpegContext; |
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static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst, |
int stride, int width, int height) |
{ |
int i; |
int code; |
int c0, c1; |
int run, copy; |
int filled = 0; |
int rows_to_go; |
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rows_to_go = height; |
height--; |
dst = dst + height * stride; |
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while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) { |
code = bytestream2_get_byte(&qctx->buffer); |
run = copy = 0; |
if(code == 0xFC) /* end-of-picture code */ |
break; |
if(code >= 0xF8) { /* very long run */ |
c0 = bytestream2_get_byte(&qctx->buffer); |
c1 = bytestream2_get_byte(&qctx->buffer); |
run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2; |
} else if (code >= 0xF0) { /* long run */ |
c0 = bytestream2_get_byte(&qctx->buffer); |
run = ((code & 0xF) << 8) + c0 + 2; |
} else if (code >= 0xE0) { /* short run */ |
run = (code & 0x1F) + 2; |
} else if (code >= 0xC0) { /* very long copy */ |
c0 = bytestream2_get_byte(&qctx->buffer); |
c1 = bytestream2_get_byte(&qctx->buffer); |
copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1; |
} else if (code >= 0x80) { /* long copy */ |
c0 = bytestream2_get_byte(&qctx->buffer); |
copy = ((code & 0x7F) << 8) + c0 + 1; |
} else { /* short copy */ |
copy = code + 1; |
} |
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/* perform actual run or copy */ |
if(run) { |
int p; |
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p = bytestream2_get_byte(&qctx->buffer); |
for(i = 0; i < run; i++) { |
dst[filled++] = p; |
if (filled >= width) { |
filled = 0; |
dst -= stride; |
rows_to_go--; |
if(rows_to_go <= 0) |
break; |
} |
} |
} else { |
for(i = 0; i < copy; i++) { |
dst[filled++] = bytestream2_get_byte(&qctx->buffer); |
if (filled >= width) { |
filled = 0; |
dst -= stride; |
rows_to_go--; |
if(rows_to_go <= 0) |
break; |
} |
} |
} |
} |
} |
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static const int qpeg_table_h[16] = |
{ 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04}; |
static const int qpeg_table_w[16] = |
{ 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04}; |
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/* Decodes delta frames */ |
static void qpeg_decode_inter(QpegContext *qctx, uint8_t *dst, |
int stride, int width, int height, |
int delta, const uint8_t *ctable, |
uint8_t *refdata) |
{ |
int i, j; |
int code; |
int filled = 0; |
int orig_height; |
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if(!refdata) |
refdata= dst; |
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/* copy prev frame */ |
for(i = 0; i < height; i++) |
memcpy(dst + (i * stride), refdata + (i * stride), width); |
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orig_height = height; |
height--; |
dst = dst + height * stride; |
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while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) { |
code = bytestream2_get_byte(&qctx->buffer); |
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if(delta) { |
/* motion compensation */ |
while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) { |
if(delta == 1) { |
int me_idx; |
int me_w, me_h, me_x, me_y; |
uint8_t *me_plane; |
int corr, val; |
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/* get block size by index */ |
me_idx = code & 0xF; |
me_w = qpeg_table_w[me_idx]; |
me_h = qpeg_table_h[me_idx]; |
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/* extract motion vector */ |
corr = bytestream2_get_byte(&qctx->buffer); |
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val = corr >> 4; |
if(val > 7) |
val -= 16; |
me_x = val; |
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val = corr & 0xF; |
if(val > 7) |
val -= 16; |
me_y = val; |
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/* check motion vector */ |
if ((me_x + filled < 0) || (me_x + me_w + filled > width) || |
(height - me_y - me_h < 0) || (height - me_y > orig_height) || |
(filled + me_w > width) || (height - me_h < 0)) |
av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n", |
me_x, me_y, me_w, me_h, filled, height); |
else { |
/* do motion compensation */ |
me_plane = refdata + (filled + me_x) + (height - me_y) * stride; |
for(j = 0; j < me_h; j++) { |
for(i = 0; i < me_w; i++) |
dst[filled + i - (j * stride)] = me_plane[i - (j * stride)]; |
} |
} |
} |
code = bytestream2_get_byte(&qctx->buffer); |
} |
} |
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if(code == 0xE0) /* end-of-picture code */ |
break; |
if(code > 0xE0) { /* run code: 0xE1..0xFF */ |
int p; |
|
code &= 0x1F; |
p = bytestream2_get_byte(&qctx->buffer); |
for(i = 0; i <= code; i++) { |
dst[filled++] = p; |
if(filled >= width) { |
filled = 0; |
dst -= stride; |
height--; |
if (height < 0) |
break; |
} |
} |
} else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */ |
code &= 0x1F; |
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if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer)) |
break; |
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for(i = 0; i <= code; i++) { |
dst[filled++] = bytestream2_get_byte(&qctx->buffer); |
if(filled >= width) { |
filled = 0; |
dst -= stride; |
height--; |
if (height < 0) |
break; |
} |
} |
} else if(code >= 0x80) { /* skip code: 0x80..0xBF */ |
int skip; |
|
code &= 0x3F; |
/* codes 0x80 and 0x81 are actually escape codes, |
skip value minus constant is in the next byte */ |
if(!code) |
skip = bytestream2_get_byte(&qctx->buffer) + 64; |
else if(code == 1) |
skip = bytestream2_get_byte(&qctx->buffer) + 320; |
else |
skip = code; |
filled += skip; |
while( filled >= width) { |
filled -= width; |
dst -= stride; |
height--; |
if(height < 0) |
break; |
} |
} else { |
/* zero code treated as one-pixel skip */ |
if(code) { |
dst[filled++] = ctable[code & 0x7F]; |
} |
else |
filled++; |
if(filled >= width) { |
filled = 0; |
dst -= stride; |
height--; |
} |
} |
} |
} |
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static int decode_frame(AVCodecContext *avctx, |
void *data, int *got_frame, |
AVPacket *avpkt) |
{ |
uint8_t ctable[128]; |
QpegContext * const a = avctx->priv_data; |
AVFrame * p = &a->pic; |
AVFrame * ref= &a->ref; |
uint8_t* outdata; |
int delta, ret; |
const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); |
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if (avpkt->size < 0x86) { |
av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); |
return AVERROR_INVALIDDATA; |
} |
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bytestream2_init(&a->buffer, avpkt->data, avpkt->size); |
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av_frame_unref(ref); |
av_frame_move_ref(ref, p); |
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if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0) |
return ret; |
outdata = a->pic.data[0]; |
bytestream2_skip(&a->buffer, 4); |
bytestream2_get_buffer(&a->buffer, ctable, 128); |
bytestream2_skip(&a->buffer, 1); |
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delta = bytestream2_get_byte(&a->buffer); |
if(delta == 0x10) { |
qpeg_decode_intra(a, outdata, a->pic.linesize[0], avctx->width, avctx->height); |
} else { |
qpeg_decode_inter(a, outdata, a->pic.linesize[0], avctx->width, avctx->height, delta, ctable, a->ref.data[0]); |
} |
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/* make the palette available on the way out */ |
if (pal) { |
a->pic.palette_has_changed = 1; |
memcpy(a->pal, pal, AVPALETTE_SIZE); |
} |
memcpy(a->pic.data[1], a->pal, AVPALETTE_SIZE); |
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if ((ret = av_frame_ref(data, &a->pic)) < 0) |
return ret; |
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*got_frame = 1; |
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return avpkt->size; |
} |
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static void decode_flush(AVCodecContext *avctx){ |
QpegContext * const a = avctx->priv_data; |
int i, pal_size; |
const uint8_t *pal_src; |
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pal_size = FFMIN(1024U, avctx->extradata_size); |
pal_src = avctx->extradata + avctx->extradata_size - pal_size; |
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for (i=0; i<pal_size/4; i++) |
a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i); |
} |
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static av_cold int decode_init(AVCodecContext *avctx){ |
QpegContext * const a = avctx->priv_data; |
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avcodec_get_frame_defaults(&a->pic); |
avcodec_get_frame_defaults(&a->ref); |
a->avctx = avctx; |
avctx->pix_fmt= AV_PIX_FMT_PAL8; |
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decode_flush(avctx); |
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avcodec_get_frame_defaults(&a->pic); |
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return 0; |
} |
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static av_cold int decode_end(AVCodecContext *avctx){ |
QpegContext * const a = avctx->priv_data; |
AVFrame * const p = &a->pic; |
AVFrame * const ref= &a->ref; |
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av_frame_unref(p); |
av_frame_unref(ref); |
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return 0; |
} |
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AVCodec ff_qpeg_decoder = { |
.name = "qpeg", |
.long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"), |
.type = AVMEDIA_TYPE_VIDEO, |
.id = AV_CODEC_ID_QPEG, |
.priv_data_size = sizeof(QpegContext), |
.init = decode_init, |
.close = decode_end, |
.decode = decode_frame, |
.flush = decode_flush, |
.capabilities = CODEC_CAP_DR1, |
}; |