ffmpeg/libavcodec/dpx.c

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/*
* DPX (.dpx) image decoder
* Copyright (c) 2009 Jimmy Christensen
*
* 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 "libavutil/intreadwrite.h"
#include "bytestream.h"
#include "avcodec.h"
typedef struct DPXContext {
AVFrame picture;
} DPXContext;
static unsigned int read32(const uint8_t **ptr, int is_big)
{
unsigned int temp;
if (is_big) {
temp = AV_RB32(*ptr);
} else {
temp = AV_RL32(*ptr);
}
*ptr += 4;
return temp;
}
static inline unsigned make_16bit(unsigned value)
{
// mask away invalid bits
value &= 0xFFC0;
// correctly expand to 16 bits
return value + (value >> 10);
}
static int decode_frame(AVCodecContext *avctx,
void *data,
int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
DPXContext *const s = avctx->priv_data;
AVFrame *picture = data;
AVFrame *const p = &s->picture;
uint8_t *ptr;
int magic_num, offset, endian;
int x, y;
int w, h, stride, bits_per_color, descriptor, elements, target_packet_size, source_packet_size;
unsigned int rgbBuffer;
magic_num = AV_RB32(buf);
buf += 4;
/* Check if the files "magic number" is "SDPX" which means it uses
* big-endian or XPDS which is for little-endian files */
if (magic_num == AV_RL32("SDPX")) {
endian = 0;
} else if (magic_num == AV_RB32("SDPX")) {
endian = 1;
} else {
av_log(avctx, AV_LOG_ERROR, "DPX marker not found\n");
return -1;
}
offset = read32(&buf, endian);
// Need to end in 0x304 offset from start of file
buf = avpkt->data + 0x304;
w = read32(&buf, endian);
h = read32(&buf, endian);
// Need to end in 0x320 to read the descriptor
buf += 20;
descriptor = buf[0];
// Need to end in 0x323 to read the bits per color
buf += 3;
avctx->bits_per_raw_sample =
bits_per_color = buf[0];
switch (descriptor) {
case 51: // RGBA
elements = 4;
break;
case 50: // RGB
elements = 3;
break;
default:
av_log(avctx, AV_LOG_ERROR, "Unsupported descriptor %d\n", descriptor);
return -1;
}
switch (bits_per_color) {
case 8:
if (elements == 4) {
avctx->pix_fmt = PIX_FMT_RGBA;
} else {
avctx->pix_fmt = PIX_FMT_RGB24;
}
source_packet_size = elements;
target_packet_size = elements;
break;
case 10:
avctx->pix_fmt = PIX_FMT_RGB48;
target_packet_size = 6;
source_packet_size = elements * 2;
break;
case 12:
case 16:
if (endian) {
avctx->pix_fmt = PIX_FMT_RGB48BE;
} else {
avctx->pix_fmt = PIX_FMT_RGB48LE;
}
target_packet_size = 6;
source_packet_size = elements * 2;
break;
default:
av_log(avctx, AV_LOG_ERROR, "Unsupported color depth : %d\n", bits_per_color);
return -1;
}
if (s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
if (avcodec_check_dimensions(avctx, w, h))
return -1;
if (w != avctx->width || h != avctx->height)
avcodec_set_dimensions(avctx, w, h);
if (avctx->get_buffer(avctx, p) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
// Move pointer to offset from start of file
buf = avpkt->data + offset;
ptr = p->data[0];
stride = p->linesize[0];
switch (bits_per_color) {
case 10:
for (x = 0; x < avctx->height; x++) {
uint16_t *dst = (uint16_t*)ptr;
for (y = 0; y < avctx->width; y++) {
rgbBuffer = read32(&buf, endian);
// Read out the 10-bit colors and convert to 16-bit
*dst++ = make_16bit(rgbBuffer >> 16);
*dst++ = make_16bit(rgbBuffer >> 6);
*dst++ = make_16bit(rgbBuffer << 4);
}
ptr += stride;
}
break;
case 8:
case 12: // Treat 12-bit as 16-bit
case 16:
if (source_packet_size == target_packet_size) {
for (x = 0; x < avctx->height; x++) {
memcpy(ptr, buf, target_packet_size*avctx->width);
ptr += stride;
buf += source_packet_size*avctx->width;
}
} else {
for (x = 0; x < avctx->height; x++) {
uint8_t *dst = ptr;
for (y = 0; y < avctx->width; y++) {
memcpy(dst, buf, target_packet_size);
dst += target_packet_size;
buf += source_packet_size;
}
ptr += stride;
}
}
break;
}
*picture = s->picture;
*data_size = sizeof(AVPicture);
return buf_size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
DPXContext *s = avctx->priv_data;
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame = &s->picture;
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
DPXContext *s = avctx->priv_data;
if (s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
return 0;
}
AVCodec dpx_decoder = {
"dpx",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_DPX,
sizeof(DPXContext),
decode_init,
NULL,
decode_end,
decode_frame,
0,
NULL,
.long_name = NULL_IF_CONFIG_SMALL("DPX image"),
};