#include "png.h"
#include "libavutil/avassert.h"
+#include "libavutil/opt.h"
/* TODO:
* - add 2, 4 and 16 bit depth support
#define IOBUF_SIZE 4096
typedef struct PNGEncContext {
+ AVClass *class;
DSPContext dsp;
uint8_t *bytestream;
z_stream zstream;
uint8_t buf[IOBUF_SIZE];
+ int dpi; ///< Physical pixel density, in dots per inch, if set
+ int dpm; ///< Physical pixel density, in dots per meter, if set
} PNGEncContext;
static void png_get_interlaced_row(uint8_t *dst, int row_size,
png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
- AV_WB32(s->buf, avctx->sample_aspect_ratio.num);
- AV_WB32(s->buf + 4, avctx->sample_aspect_ratio.den);
- s->buf[8] = 0; /* unit specifier is unknown */
+ if (s->dpm) {
+ AV_WB32(s->buf, s->dpm);
+ AV_WB32(s->buf + 4, s->dpm);
+ s->buf[8] = 1; /* unit specifier is meter */
+ } else {
+ AV_WB32(s->buf, avctx->sample_aspect_ratio.num);
+ AV_WB32(s->buf + 4, avctx->sample_aspect_ratio.den);
+ s->buf[8] = 0; /* unit specifier is unknown */
+ }
png_write_chunk(&s->bytestream, MKTAG('p', 'H', 'Y', 's'), s->buf, 9);
/* put the palette if needed */
if(avctx->pix_fmt == AV_PIX_FMT_MONOBLACK)
s->filter_type = PNG_FILTER_VALUE_NONE;
+ if (s->dpi && s->dpm) {
+ av_log(avctx, AV_LOG_ERROR, "Only one of 'dpi' or 'dpm' options should be set\n");
+ return AVERROR(EINVAL);
+ } else if (s->dpi) {
+ s->dpm = s->dpi * 10000 / 254;
+ }
+
return 0;
}
+#define OFFSET(x) offsetof(PNGEncContext, x)
+#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+ {"dpi", "Set image resolution (in dots per inch)", OFFSET(dpi), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE},
+ {"dpm", "Set image resolution (in dots per meter)", OFFSET(dpm), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 0x10000, VE},
+ { NULL }
+};
+
+static const AVClass pngenc_class = {
+ .class_name = "PNG encoder",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
AVCodec ff_png_encoder = {
.name = "png",
.type = AVMEDIA_TYPE_VIDEO,
AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE
},
.long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
+ .priv_class = &pngenc_class,
};