ffmpeg/libavcodec/jvdec.c

233 lines
6.6 KiB
C

/*
* Bitmap Brothers JV video decoder
* Copyright (c) 2011 Peter Ross <pross@xvid.org>
*
* 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
* Bitmap Brothers JV video decoder
* @author Peter Ross <pross@xvid.org>
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bitstream.h"
#include "blockdsp.h"
#include "internal.h"
typedef struct JvContext {
BlockDSPContext bdsp;
AVFrame *frame;
uint32_t palette[AVPALETTE_COUNT];
int palette_has_changed;
} JvContext;
static av_cold int decode_init(AVCodecContext *avctx)
{
JvContext *s = avctx->priv_data;
if (!avctx->width || !avctx->height ||
(avctx->width & 7) || (avctx->height & 7)) {
av_log(avctx, AV_LOG_ERROR, "Invalid video dimensions: %dx%d\n",
avctx->width, avctx->height);
return AVERROR(EINVAL);
}
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
avctx->pix_fmt = AV_PIX_FMT_PAL8;
ff_blockdsp_init(&s->bdsp);
return 0;
}
/**
* Decode 2x2 block
*/
static inline void decode2x2(BitstreamContext *bc, uint8_t *dst, int linesize)
{
int i, j, v[2];
switch (bitstream_read(bc, 2)) {
case 1:
v[0] = bitstream_read(bc, 8);
for (j = 0; j < 2; j++)
memset(dst + j * linesize, v[0], 2);
break;
case 2:
v[0] = bitstream_read(bc, 8);
v[1] = bitstream_read(bc, 8);
for (j = 0; j < 2; j++)
for (i = 0; i < 2; i++)
dst[j * linesize + i] = v[bitstream_read_bit(bc)];
break;
case 3:
for (j = 0; j < 2; j++)
for (i = 0; i < 2; i++)
dst[j * linesize + i] = bitstream_read(bc, 8);
}
}
/**
* Decode 4x4 block
*/
static inline void decode4x4(BitstreamContext *bc, uint8_t *dst, int linesize)
{
int i, j, v[2];
switch (bitstream_read(bc, 2)) {
case 1:
v[0] = bitstream_read(bc, 8);
for (j = 0; j < 4; j++)
memset(dst + j * linesize, v[0], 4);
break;
case 2:
v[0] = bitstream_read(bc, 8);
v[1] = bitstream_read(bc, 8);
for (j = 2; j >= 0; j -= 2) {
for (i = 0; i < 4; i++)
dst[j * linesize + i] = v[bitstream_read_bit(bc)];
for (i = 0; i < 4; i++)
dst[(j + 1) * linesize + i] = v[bitstream_read_bit(bc)];
}
break;
case 3:
for (j = 0; j < 4; j += 2)
for (i = 0; i < 4; i += 2)
decode2x2(bc, dst + j * linesize + i, linesize);
}
}
/**
* Decode 8x8 block
*/
static inline void decode8x8(BitstreamContext *bc, uint8_t *dst, int linesize,
BlockDSPContext *bdsp)
{
int i, j, v[2];
switch (bitstream_read(bc, 2)) {
case 1:
v[0] = bitstream_read(bc, 8);
bdsp->fill_block_tab[1](dst, v[0], linesize, 8);
break;
case 2:
v[0] = bitstream_read(bc, 8);
v[1] = bitstream_read(bc, 8);
for (j = 7; j >= 0; j--)
for (i = 0; i < 8; i++)
dst[j * linesize + i] = v[bitstream_read_bit(bc)];
break;
case 3:
for (j = 0; j < 8; j += 4)
for (i = 0; i < 8; i += 4)
decode4x4(bc, dst + j * linesize + i, linesize);
}
}
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
JvContext *s = avctx->priv_data;
int buf_size = avpkt->size;
const uint8_t *buf = avpkt->data;
const uint8_t *buf_end = buf + buf_size;
int video_size, video_type, i, j, ret;
video_size = AV_RL32(buf);
video_type = buf[4];
buf += 5;
if (video_size) {
if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
if (video_type == 0 || video_type == 1) {
BitstreamContext bc;
bitstream_init8(&bc, buf, FFMIN(video_size, buf_end - buf));
for (j = 0; j < avctx->height; j += 8)
for (i = 0; i < avctx->width; i += 8)
decode8x8(&bc,
s->frame->data[0] + j * s->frame->linesize[0] + i,
s->frame->linesize[0], &s->bdsp);
buf += video_size;
} else if (video_type == 2) {
if (buf + 1 <= buf_end) {
int v = *buf++;
for (j = 0; j < avctx->height; j++)
memset(s->frame->data[0] + j * s->frame->linesize[0],
v, avctx->width);
}
} else {
av_log(avctx, AV_LOG_WARNING,
"unsupported frame type %i\n", video_type);
return AVERROR_INVALIDDATA;
}
}
if (buf < buf_end) {
for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) {
s->palette[i] = AV_RB24(buf) << 2;
buf += 3;
}
s->palette_has_changed = 1;
}
if (video_size) {
s->frame->key_frame = 1;
s->frame->pict_type = AV_PICTURE_TYPE_I;
s->frame->palette_has_changed = s->palette_has_changed;
s->palette_has_changed = 0;
memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
if ((ret = av_frame_ref(data, s->frame)) < 0)
return ret;
*got_frame = 1;
}
return buf_size;
}
static av_cold int decode_close(AVCodecContext *avctx)
{
JvContext *s = avctx->priv_data;
av_frame_free(&s->frame);
return 0;
}
AVCodec ff_jv_decoder = {
.name = "jv",
.long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_JV,
.priv_data_size = sizeof(JvContext),
.init = decode_init,
.close = decode_close,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};