| Message ID | 20230308200316.45476-2-leo.izen@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | PNG sBIT chunk support | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
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, \
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.
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, \
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(-)