ffmpeg/libavcodec/hdrdec.c

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/*
* Radiance HDR image format
*
* 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 "codec_internal.h"
#include "decode.h"
#include "thread.h"
#define MINELEN 8
#define MAXELEN 0x7fff
static int hdr_get_line(GetByteContext *gb, uint8_t *buffer, int size)
{
int n = 0, c;
memset(buffer, 0, size);
do {
c = bytestream2_get_byte(gb);
if (n < size - 1)
buffer[n++] = c;
} while (bytestream2_get_bytes_left(gb) > 0 && c != '\n');
return 0;
}
static float convert(int expo, int val)
{
if (expo == -128) {
return 0.f;
} else {
const float v = val / 256.f;
return ldexpf(v, expo);
}
}
static int decompress(uint8_t *scanline, int w, GetByteContext *gb, const uint8_t *start)
{
int rshift = 0;
while (w > 0) {
if (bytestream2_get_bytes_left(gb) < 4)
return AVERROR_INVALIDDATA;
scanline[0] = bytestream2_get_byte(gb);
scanline[1] = bytestream2_get_byte(gb);
scanline[2] = bytestream2_get_byte(gb);
scanline[3] = bytestream2_get_byte(gb);
if (scanline[0] == 1 &&
scanline[1] == 1 &&
scanline[2] == 1) {
int run = scanline[3];
for (int i = run << rshift; i > 0 && w > 0 && scanline >= start + 4; i--) {
memcpy(scanline, scanline - 4, 4);
scanline += 4;
w -= 4;
}
rshift += 8;
if (rshift > 16)
break;
} else {
scanline += 4;
w--;
rshift = 0;
}
}
return 1;
}
static int hdr_decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
int width = 0, height = 0;
GetByteContext gb;
uint8_t line[512];
float sar;
int ret;
bytestream2_init(&gb, avpkt->data, avpkt->size);
hdr_get_line(&gb, line, sizeof(line));
if (memcmp("#?RADIANCE\n", line, 11))
return AVERROR_INVALIDDATA;
do {
hdr_get_line(&gb, line, sizeof(line));
if (sscanf(line, "PIXASPECT=%f\n", &sar) == 1)
avctx->sample_aspect_ratio = p->sample_aspect_ratio = av_inv_q(av_d2q(sar, 4096));
} while (line[0] != '\n' && line[0]);
hdr_get_line(&gb, line, sizeof(line));
if (sscanf(line, "-Y %d +X %d\n", &height, &width) == 2) {
;
} else if (sscanf(line, "+Y %d +X %d\n", &height, &width) == 2) {
;
} else if (sscanf(line, "-Y %d -X %d\n", &height, &width) == 2) {
;
} else if (sscanf(line, "+Y %d -X %d\n", &height, &width) == 2) {
;
} else if (sscanf(line, "-X %d +Y %d\n", &width, &height) == 2) {
;
} else if (sscanf(line, "+X %d +Y %d\n", &width, &height) == 2) {
;
} else if (sscanf(line, "-X %d -Y %d\n", &width, &height) == 2) {
;
} else if (sscanf(line, "+X %d -Y %d\n", &width, &height) == 2) {
;
}
if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
return ret;
avctx->pix_fmt = AV_PIX_FMT_GBRPF32;
if (avctx->skip_frame >= AVDISCARD_ALL)
return avpkt->size;
if ((ret = ff_thread_get_buffer(avctx, p, 0)) < 0)
return ret;
for (int y = 0; y < height; y++) {
float *dst_r = (float *)(p->data[2] + y * p->linesize[2]);
float *dst_g = (float *)(p->data[0] + y * p->linesize[0]);
float *dst_b = (float *)(p->data[1] + y * p->linesize[1]);
uint8_t *scanline = p->data[0] + y * p->linesize[0];
int i;
if (width < MINELEN || width > MAXELEN) {
ret = decompress(scanline, width, &gb, scanline);
if (ret < 0)
return ret;
goto convert;
}
i = bytestream2_peek_byte(&gb);
if (i != 2) {
ret = decompress(scanline, width, &gb, scanline);
if (ret < 0)
return ret;
goto convert;
}
bytestream2_skip(&gb, 1);
scanline[1] = bytestream2_get_byte(&gb);
scanline[2] = bytestream2_get_byte(&gb);
i = bytestream2_get_byte(&gb);
if (scanline[1] != 2 || scanline[2] & 128) {
scanline[0] = 2;
scanline[3] = i;
ret = decompress(scanline + 4, width - 1, &gb, scanline);
if (ret < 0)
return ret;
goto convert;
}
for (int i = 0; i < 4; i++) {
uint8_t *scanline = p->data[0] + y * p->linesize[0] + i;
for (int j = 0; j < width * 4 && bytestream2_get_bytes_left(&gb) > 0;) {
int run = bytestream2_get_byte(&gb);
if (run > 128) {
uint8_t val = bytestream2_get_byte(&gb);
run &= 127;
while (run--) {
if (j >= width * 4)
break;
scanline[j] = val;
j += 4;
}
} else if (run > 0) {
while (run--) {
if (j >= width * 4)
break;
scanline[j] = bytestream2_get_byte(&gb);
j += 4;
}
}
}
}
convert:
for (int x = 0; x < width; x++) {
uint8_t rgbe[4];
int expo;
memcpy(rgbe, p->data[0] + y * p->linesize[0] + x * 4, 4);
expo = rgbe[3] - 128;
dst_r[x] = convert(expo, rgbe[0]);
dst_b[x] = convert(expo, rgbe[2]);
dst_g[x] = convert(expo, rgbe[1]);
}
}
p->flags |= AV_FRAME_FLAG_KEY;
p->pict_type = AV_PICTURE_TYPE_I;
*got_frame = 1;
return avpkt->size;
}
const FFCodec ff_hdr_decoder = {
.p.name = "hdr",
CODEC_LONG_NAME("HDR (Radiance RGBE format) image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_RADIANCE_HDR,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
FF_CODEC_DECODE_CB(hdr_decode_frame),
};