From 31acdf4351a13195baa8ab453f4429d150dc25a2 Mon Sep 17 00:00:00 2001 From: Nick Renieris Date: Thu, 29 Aug 2019 16:10:49 +0300 Subject: lavc/tiff: Support decoding of DNGs with single-component JPEGs This enables decoding of DNG images generated by the 'DJI Zenmuse X7' digital camera Samples: https://www.dji.com/gr/zenmuse-x7/info#downloads Signed-off-by: Nick Renieris --- libavcodec/tiff.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 51 insertions(+), 10 deletions(-) diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c index bdc9335b9a..4b40df73f9 100644 --- a/libavcodec/tiff.c +++ b/libavcodec/tiff.c @@ -274,7 +274,8 @@ static int add_metadata(int count, int type, } static void av_always_inline dng_blit(TiffContext *s, uint8_t *dst, int dst_stride, - const uint8_t *src, int src_stride, int width, int height, int is_u16); + const uint8_t *src, int src_stride, int width, int height, + int is_single_comp, int is_u16); static void av_always_inline horizontal_fill(TiffContext *s, unsigned int bpp, uint8_t* dst, @@ -698,6 +699,7 @@ static int tiff_unpack_strip(TiffContext *s, AVFrame *p, uint8_t *dst, int strid 0, // no stride, only 1 line width / pixel_size_bytes * pixel_size_bits / s->bpp * s->bppcount, // need to account for [1, 16] bpp 1, + 0, // single-component variation is only preset in JPEG-encoded DNGs is_u16); } @@ -795,18 +797,32 @@ static uint16_t av_always_inline dng_process_color8(uint16_t value, static void dng_blit(TiffContext *s, uint8_t *dst, int dst_stride, const uint8_t *src, int src_stride, - int width, int height, int is_u16) + int width, int height, int is_single_comp, int is_u16) { int line, col; float scale_factor; scale_factor = 1.0f / (s->white_level - s->black_level); - if (is_u16) { - for (line = 0; line < height; line++) { + if (is_single_comp) { + if (!is_u16) + return; /* <= 8bpp unsupported */ + + /* Image is double the width and half the height we need, each row comprises 2 rows of the output + (split vertically in the middle). */ + for (line = 0; line < height / 2; line++) { uint16_t *dst_u16 = (uint16_t *)dst; uint16_t *src_u16 = (uint16_t *)src; + /* Blit first half of input row row to initial row of output */ + for (col = 0; col < width; col++) + *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor); + + /* Advance the destination pointer by a row (source pointer remains in the same place) */ + dst += dst_stride * sizeof(uint16_t); + dst_u16 = (uint16_t *)dst; + + /* Blit second half of input row row to next row of output */ for (col = 0; col < width; col++) *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor); @@ -814,12 +830,27 @@ static void dng_blit(TiffContext *s, uint8_t *dst, int dst_stride, src += src_stride * sizeof(uint16_t); } } else { - for (line = 0; line < height; line++) { - for (col = 0; col < width; col++) - *dst++ = dng_process_color8(*src++, s->dng_lut, s->black_level, scale_factor); + /* Input and output image are the same size and the MJpeg decoder has done per-component + deinterleaving, so blitting here is straightforward. */ + if (is_u16) { + for (line = 0; line < height; line++) { + uint16_t *dst_u16 = (uint16_t *)dst; + uint16_t *src_u16 = (uint16_t *)src; + + for (col = 0; col < width; col++) + *dst_u16++ = dng_process_color16(*src_u16++, s->dng_lut, s->black_level, scale_factor); + + dst += dst_stride * sizeof(uint16_t); + src += src_stride * sizeof(uint16_t); + } + } else { + for (line = 0; line < height; line++) { + for (col = 0; col < width; col++) + *dst++ = dng_process_color8(*src++, s->dng_lut, s->black_level, scale_factor); - dst += dst_stride; - src += src_stride; + dst += dst_stride; + src += src_stride; + } } } } @@ -831,7 +862,7 @@ static int dng_decode_jpeg_tile(AVCodecContext *avctx, AVFrame *frame, AVPacket jpkt; uint8_t *dst_data, *src_data; uint32_t dst_offset; /* offset from dst buffer in pixels */ - int is_u16, pixel_size; + int is_single_comp, is_u16, pixel_size; int ret; /* Prepare a packet and send to the MJPEG decoder */ @@ -865,9 +896,18 @@ static int dng_decode_jpeg_tile(AVCodecContext *avctx, AVFrame *frame, /* Copy the outputted tile's pixels from 'jpgframe' to 'frame' (final buffer) */ + /* See dng_blit for explanation */ + is_single_comp = (s->avctx_mjpeg->width == w * 2 && s->avctx_mjpeg->height == h / 2); + is_u16 = (s->bpp > 8); pixel_size = (is_u16 ? sizeof(uint16_t) : sizeof(uint8_t)); + if (is_single_comp && !is_u16) { + av_log(s->avctx, AV_LOG_ERROR, "DNGs with bpp <= 8 and 1 component are unsupported\n"); + av_frame_unref(s->jpgframe); + return AVERROR_PATCHWELCOME; + } + dst_offset = x + frame->linesize[0] * y / pixel_size; dst_data = frame->data[0] + dst_offset * pixel_size; src_data = s->jpgframe->data[0]; @@ -879,6 +919,7 @@ static int dng_decode_jpeg_tile(AVCodecContext *avctx, AVFrame *frame, s->jpgframe->linesize[0] / pixel_size, w, h, + is_single_comp, is_u16); av_frame_unref(s->jpgframe); -- cgit v1.2.3