* [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support
@ 2023-03-08 20:03 Leo Izen
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks Leo Izen
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Leo Izen @ 2023-03-08 20:03 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Leo Izen
Add support to the PNG decoder and encoder to support sBIT chunks,
by using AVCodecContext->bits_per_raw_sample.
Leo Izen (2):
avcodec/pngdec: support sBIT chunks
avcodec/pngenc: write sBIT chunks
libavcodec/pngdec.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
libavcodec/pngenc.c | 6 ++++++
libavcodec/version.h | 2 +-
3 files changed, 52 insertions(+), 1 deletion(-)
--
2.39.2
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* [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks
2023-03-08 20:03 [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
@ 2023-03-08 20:03 ` Leo Izen
2023-03-16 1:32 ` Andreas Rheinhardt
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 2/2] avcodec/pngenc: write " Leo Izen
2023-03-15 19:15 ` [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
2 siblings, 1 reply; 6+ messages in thread
From: Leo Izen @ 2023-03-08 20:03 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Leo Izen
Add support for reading sBIT chunks, which mark the significant
bit depth of the PNG file. This passes the metadata using the field
bits_per_raw_sample of AVCodecContext.
Signed-off-by: Leo Izen <leo.izen@gmail.com>
---
libavcodec/pngdec.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
libavcodec/version.h | 2 +-
2 files changed, 46 insertions(+), 1 deletion(-)
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 9403d72f2f..3c91896c9b 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -98,6 +98,7 @@ typedef struct PNGDecContext {
int bpp;
int has_trns;
uint8_t transparent_color_be[6];
+ int significant_bits;
uint32_t palette[256];
uint8_t *crow_buf;
@@ -716,6 +717,14 @@ static int populate_avctx_color_fields(AVCodecContext *avctx, AVFrame *frame)
avctx->colorspace = frame->colorspace = AVCOL_SPC_RGB;
avctx->color_range = frame->color_range = AVCOL_RANGE_JPEG;
+ /*
+ * tRNS sets alpha depth to full, so we ignore sBIT if set.
+ * As a result we must wait until now to set
+ * avctx->bits_per_raw_sample in case tRNS appears after sBIT
+ */
+ if (!s->has_trns && s->significant_bits > 0)
+ avctx->bits_per_raw_sample = s->significant_bits;
+
return 0;
}
@@ -996,6 +1005,38 @@ fail:
return ret;
}
+static int decode_sbit_chunk(AVCodecContext *avctx, PNGDecContext *s,
+ GetByteContext *gb)
+{
+ int bits = 0;
+ int channels;
+
+ if (!(s->hdr_state & PNG_IHDR)) {
+ av_log(avctx, AV_LOG_ERROR, "sBIT before IHDR\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ if (s->pic_state & PNG_IDAT) {
+ av_log(avctx, AV_LOG_ERROR, "sBIT after IDAT\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ channels = ff_png_get_nb_channels(s->color_type);
+
+ for (int i = 0; i < channels; i++) {
+ int b = bytestream2_get_byteu(gb);
+ bits = FFMAX(b, bits);
+ }
+
+ if (bits < 0 || bits > s->bit_depth) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid significant bits: %d\n", bits);
+ return AVERROR_INVALIDDATA;
+ }
+ s->significant_bits = bits;
+
+ return 0;
+}
+
static void handle_small_bpp(PNGDecContext *s, AVFrame *p)
{
if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE) {
@@ -1440,6 +1481,10 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
break;
}
+ case MKTAG('s', 'B', 'I', 'T'):
+ if ((ret = decode_sbit_chunk(avctx, s, &gb_chunk)) < 0)
+ goto fail;
+ break;
case MKTAG('g', 'A', 'M', 'A'): {
AVBPrint bp;
char *gamma_str;
diff --git a/libavcodec/version.h b/libavcodec/version.h
index da54f87887..39dbec0208 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -30,7 +30,7 @@
#include "version_major.h"
#define LIBAVCODEC_VERSION_MINOR 6
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \
--
2.39.2
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^ permalink raw reply [flat|nested] 6+ messages in thread
* [FFmpeg-devel] [PATCH v2 2/2] avcodec/pngenc: write sBIT chunks
2023-03-08 20:03 [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks Leo Izen
@ 2023-03-08 20:03 ` Leo Izen
2023-03-15 19:15 ` [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
2 siblings, 0 replies; 6+ messages in thread
From: Leo Izen @ 2023-03-08 20:03 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Leo Izen
Add support for writing sBIT chunks, which mark the significant
bit depth of the PNG file. This obtains the metadata using the field
bits_per_raw_sample of AVCodecContext.
Signed-off-by: Leo Izen <leo.izen@gmail.com>
---
libavcodec/pngenc.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c
index 1489256d00..21b033ea16 100644
--- a/libavcodec/pngenc.c
+++ b/libavcodec/pngenc.c
@@ -442,6 +442,12 @@ static int encode_headers(AVCodecContext *avctx, const AVFrame *pict)
if (png_get_gama(pict->color_trc, s->buf))
png_write_chunk(&s->bytestream, MKTAG('g', 'A', 'M', 'A'), s->buf, 4);
+ if (avctx->bits_per_raw_sample > 0 && avctx->bits_per_raw_sample < s->bit_depth) {
+ int len = ff_png_get_nb_channels(s->color_type);
+ memset(s->buf, avctx->bits_per_raw_sample, len);
+ png_write_chunk(&s->bytestream, MKTAG('s', 'B', 'I', 'T'), s->buf, len);
+ }
+
/* put the palette if needed, must be after colorspace information */
if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
int has_alpha, alpha, i;
--
2.39.2
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support
2023-03-08 20:03 [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks Leo Izen
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 2/2] avcodec/pngenc: write " Leo Izen
@ 2023-03-15 19:15 ` Leo Izen
2 siblings, 0 replies; 6+ messages in thread
From: Leo Izen @ 2023-03-15 19:15 UTC (permalink / raw)
To: ffmpeg-devel
On 3/8/23 15:03, Leo Izen wrote:
> Add support to the PNG decoder and encoder to support sBIT chunks,
> by using AVCodecContext->bits_per_raw_sample.
>
> Leo Izen (2):
> avcodec/pngdec: support sBIT chunks
> avcodec/pngenc: write sBIT chunks
>
> libavcodec/pngdec.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
> libavcodec/pngenc.c | 6 ++++++
> libavcodec/version.h | 2 +-
> 3 files changed, 52 insertions(+), 1 deletion(-)
>
Will merge in a few days if there's no other objections or comments.
- Leo Izen (thebombzen)
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks Leo Izen
@ 2023-03-16 1:32 ` Andreas Rheinhardt
2023-03-16 15:52 ` Leo Izen
0 siblings, 1 reply; 6+ messages in thread
From: Andreas Rheinhardt @ 2023-03-16 1:32 UTC (permalink / raw)
To: ffmpeg-devel
Leo Izen:
> Add support for reading sBIT chunks, which mark the significant
> bit depth of the PNG file. This passes the metadata using the field
> bits_per_raw_sample of AVCodecContext.
>
> Signed-off-by: Leo Izen <leo.izen@gmail.com>
> ---
> libavcodec/pngdec.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
> libavcodec/version.h | 2 +-
> 2 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
> index 9403d72f2f..3c91896c9b 100644
> --- a/libavcodec/pngdec.c
> +++ b/libavcodec/pngdec.c
> @@ -98,6 +98,7 @@ typedef struct PNGDecContext {
> int bpp;
> int has_trns;
> uint8_t transparent_color_be[6];
> + int significant_bits;
>
> uint32_t palette[256];
> uint8_t *crow_buf;
> @@ -716,6 +717,14 @@ static int populate_avctx_color_fields(AVCodecContext *avctx, AVFrame *frame)
> avctx->colorspace = frame->colorspace = AVCOL_SPC_RGB;
> avctx->color_range = frame->color_range = AVCOL_RANGE_JPEG;
>
> + /*
> + * tRNS sets alpha depth to full, so we ignore sBIT if set.
> + * As a result we must wait until now to set
> + * avctx->bits_per_raw_sample in case tRNS appears after sBIT
> + */
> + if (!s->has_trns && s->significant_bits > 0)
> + avctx->bits_per_raw_sample = s->significant_bits;
> +
> return 0;
> }
>
> @@ -996,6 +1005,38 @@ fail:
> return ret;
> }
>
> +static int decode_sbit_chunk(AVCodecContext *avctx, PNGDecContext *s,
> + GetByteContext *gb)
> +{
> + int bits = 0;
> + int channels;
> +
> + if (!(s->hdr_state & PNG_IHDR)) {
> + av_log(avctx, AV_LOG_ERROR, "sBIT before IHDR\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + if (s->pic_state & PNG_IDAT) {
> + av_log(avctx, AV_LOG_ERROR, "sBIT after IDAT\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + channels = ff_png_get_nb_channels(s->color_type);
> +
> + for (int i = 0; i < channels; i++) {
> + int b = bytestream2_get_byteu(gb);
What ensures that there is enough input left?
> + bits = FFMAX(b, bits);
> + }
> +
> + if (bits < 0 || bits > s->bit_depth) {
> + av_log(avctx, AV_LOG_ERROR, "Invalid significant bits: %d\n", bits);
> + return AVERROR_INVALIDDATA;
> + }
> + s->significant_bits = bits;
> +
> + return 0;
> +}
> +
> static void handle_small_bpp(PNGDecContext *s, AVFrame *p)
> {
> if (s->bits_per_pixel == 1 && s->color_type == PNG_COLOR_TYPE_PALETTE) {
> @@ -1440,6 +1481,10 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
>
> break;
> }
> + case MKTAG('s', 'B', 'I', 'T'):
> + if ((ret = decode_sbit_chunk(avctx, s, &gb_chunk)) < 0)
> + goto fail;
> + break;
> case MKTAG('g', 'A', 'M', 'A'): {
> AVBPrint bp;
> char *gamma_str;
> diff --git a/libavcodec/version.h b/libavcodec/version.h
> index da54f87887..39dbec0208 100644
> --- a/libavcodec/version.h
> +++ b/libavcodec/version.h
> @@ -30,7 +30,7 @@
> #include "version_major.h"
>
> #define LIBAVCODEC_VERSION_MINOR 6
> -#define LIBAVCODEC_VERSION_MICRO 100
> +#define LIBAVCODEC_VERSION_MICRO 101
>
> #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
> LIBAVCODEC_VERSION_MINOR, \
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks
2023-03-16 1:32 ` Andreas Rheinhardt
@ 2023-03-16 15:52 ` Leo Izen
0 siblings, 0 replies; 6+ messages in thread
From: Leo Izen @ 2023-03-16 15:52 UTC (permalink / raw)
To: ffmpeg-devel
On 3/15/23 21:32, Andreas Rheinhardt wrote:
> Leo Izen:
>> Add support for reading sBIT chunks, which mark the significant
>> bit depth of the PNG file. This passes the metadata using the field
>> bits_per_raw_sample of AVCodecContext.
>>
>> Signed-off-by: Leo Izen <leo.izen@gmail.com>
>> ---
>> libavcodec/pngdec.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
>> libavcodec/version.h | 2 +-
>> 2 files changed, 46 insertions(+), 1 deletion(-)
>>
>> diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
>> index 9403d72f2f..3c91896c9b 100644
>> --- a/libavcodec/pngdec.c
>> +++ b/libavcodec/pngdec.c
>> @@ -98,6 +98,7 @@ typedef struct PNGDecContext {
>> int bpp;
>> int has_trns;
>> uint8_t transparent_color_be[6];
>> + int significant_bits;
>>
>> uint32_t palette[256];
>> uint8_t *crow_buf;
>> @@ -716,6 +717,14 @@ static int populate_avctx_color_fields(AVCodecContext *avctx, AVFrame *frame)
>> avctx->colorspace = frame->colorspace = AVCOL_SPC_RGB;
>> avctx->color_range = frame->color_range = AVCOL_RANGE_JPEG;
>>
>> + /*
>> + * tRNS sets alpha depth to full, so we ignore sBIT if set.
>> + * As a result we must wait until now to set
>> + * avctx->bits_per_raw_sample in case tRNS appears after sBIT
>> + */
>> + if (!s->has_trns && s->significant_bits > 0)
>> + avctx->bits_per_raw_sample = s->significant_bits;
>> +
>> return 0;
>> }
>>
>> @@ -996,6 +1005,38 @@ fail:
>> return ret;
>> }
>>
>> +static int decode_sbit_chunk(AVCodecContext *avctx, PNGDecContext *s,
>> + GetByteContext *gb)
>> +{
>> + int bits = 0;
>> + int channels;
>> +
>> + if (!(s->hdr_state & PNG_IHDR)) {
>> + av_log(avctx, AV_LOG_ERROR, "sBIT before IHDR\n");
>> + return AVERROR_INVALIDDATA;
>> + }
>> +
>> + if (s->pic_state & PNG_IDAT) {
>> + av_log(avctx, AV_LOG_ERROR, "sBIT after IDAT\n");
>> + return AVERROR_INVALIDDATA;
>> + }
>> +
>> + channels = ff_png_get_nb_channels(s->color_type);
>> +
>> + for (int i = 0; i < channels; i++) {
>> + int b = bytestream2_get_byteu(gb);
>
> What ensures that there is enough input left?
>
Good catch, I missed a call to bytestream2_get_bytes_left.
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-03-16 15:52 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-08 20:03 [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 1/2] avcodec/pngdec: support sBIT chunks Leo Izen
2023-03-16 1:32 ` Andreas Rheinhardt
2023-03-16 15:52 ` Leo Izen
2023-03-08 20:03 ` [FFmpeg-devel] [PATCH v2 2/2] avcodec/pngenc: write " Leo Izen
2023-03-15 19:15 ` [FFmpeg-devel] [PATCH v2 0/2] PNG sBIT chunk support Leo Izen
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