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dec_frame.h (14103B)


      1 // Copyright (c) the JPEG XL Project Authors. All rights reserved.
      2 //
      3 // Use of this source code is governed by a BSD-style
      4 // license that can be found in the LICENSE file.
      5 
      6 #ifndef LIB_JXL_DEC_FRAME_H_
      7 #define LIB_JXL_DEC_FRAME_H_
      8 
      9 #include <jxl/decode.h>
     10 #include <jxl/types.h>
     11 
     12 #include <algorithm>
     13 #include <cstddef>
     14 #include <cstdint>
     15 #include <limits>
     16 #include <utility>
     17 #include <vector>
     18 
     19 #include "lib/jxl/base/common.h"
     20 #include "lib/jxl/base/compiler_specific.h"
     21 #include "lib/jxl/base/data_parallel.h"
     22 #include "lib/jxl/base/status.h"
     23 #include "lib/jxl/common.h"  // JXL_HIGH_PRECISION
     24 #include "lib/jxl/dec_bit_reader.h"
     25 #include "lib/jxl/dec_cache.h"
     26 #include "lib/jxl/dec_modular.h"
     27 #include "lib/jxl/frame_header.h"
     28 #include "lib/jxl/image_bundle.h"
     29 #include "lib/jxl/image_metadata.h"
     30 
     31 namespace jxl {
     32 
     33 // Decodes a frame. Groups may be processed in parallel by `pool`.
     34 // `metadata` is the metadata that applies to all frames of the codestream
     35 // `decoded->metadata` must already be set and must match metadata.m.
     36 // Used in the encoder to model decoder behaviour, and in tests.
     37 Status DecodeFrame(PassesDecoderState* dec_state, ThreadPool* JXL_RESTRICT pool,
     38                   const uint8_t* next_in, size_t avail_in,
     39                   FrameHeader* frame_header, ImageBundle* decoded,
     40                   const CodecMetadata& metadata,
     41                   bool use_slow_rendering_pipeline = false);
     42 
     43 // TODO(veluca): implement "forced drawing".
     44 class FrameDecoder {
     45 public:
     46  // All parameters must outlive the FrameDecoder.
     47  FrameDecoder(PassesDecoderState* dec_state, const CodecMetadata& metadata,
     48               ThreadPool* pool, bool use_slow_rendering_pipeline)
     49      : dec_state_(dec_state),
     50        pool_(pool),
     51        frame_header_(&metadata),
     52        modular_frame_decoder_(dec_state_->memory_manager()),
     53        use_slow_rendering_pipeline_(use_slow_rendering_pipeline) {}
     54 
     55  void SetRenderSpotcolors(bool rsc) { render_spotcolors_ = rsc; }
     56  void SetCoalescing(bool c) { coalescing_ = c; }
     57 
     58  // Read FrameHeader and table of contents from the given BitReader.
     59  Status InitFrame(BitReader* JXL_RESTRICT br, ImageBundle* decoded,
     60                   bool is_preview);
     61 
     62  // Checks frame dimensions for their limits, and sets the output
     63  // image buffer.
     64  Status InitFrameOutput();
     65 
     66  struct SectionInfo {
     67    BitReader* JXL_RESTRICT br;
     68    // Logical index of the section, regardless of any permutation that may be
     69    // applied in the table of contents or of the physical position in the file.
     70    size_t id;
     71    // Index of the section in the order of the bytes inside the frame.
     72    size_t index;
     73  };
     74 
     75  struct TocEntry {
     76    size_t size;
     77    size_t id;
     78  };
     79 
     80  enum SectionStatus {
     81    // Processed correctly.
     82    kDone = 0,
     83    // Skipped because other required sections were not yet processed.
     84    kSkipped = 1,
     85    // Skipped because the section was already processed.
     86    kDuplicate = 2,
     87    // Only partially decoded: the section will need to be processed again.
     88    kPartial = 3,
     89  };
     90 
     91  // Processes `num` sections; each SectionInfo contains the index
     92  // of the section and a BitReader that only contains the data of the section.
     93  // `section_status` should point to `num` elements, and will be filled with
     94  // information about whether each section was processed or not.
     95  // A section is a part of the encoded file that is indexed by the TOC.
     96  Status ProcessSections(const SectionInfo* sections, size_t num,
     97                         SectionStatus* section_status);
     98 
     99  // Flushes all the data decoded so far to pixels.
    100  Status Flush();
    101 
    102  // Runs final operations once a frame data is decoded.
    103  // Must be called exactly once per frame, after all calls to ProcessSections.
    104  Status FinalizeFrame();
    105 
    106  // Returns dependencies of this frame on reference ids as a bit mask: bits 0-3
    107  // indicate reference frame 0-3 for patches and blending, bits 4-7 indicate DC
    108  // frames this frame depends on. Only returns a valid result after all calls
    109  // to ProcessSections are finished and before FinalizeFrame.
    110  int References() const;
    111 
    112  // Returns reference id of storage location where this frame is stored as a
    113  // bit flag, or 0 if not stored.
    114  // Matches the bit mask used for GetReferences: bits 0-3 indicate it is stored
    115  // for patching or blending, bits 4-7 indicate DC frame.
    116  // Unlike References, can be ran at any time as
    117  // soon as the frame header is known.
    118  static int SavedAs(const FrameHeader& header);
    119 
    120  uint64_t SumSectionSizes() const { return section_sizes_sum_; }
    121  const std::vector<TocEntry>& Toc() const { return toc_; }
    122 
    123  const FrameHeader& GetFrameHeader() const { return frame_header_; }
    124 
    125  // Returns whether a DC image has been decoded, accessible at low resolution
    126  // at passes.shared_storage.dc_storage
    127  bool HasDecodedDC() const { return finalized_dc_; }
    128  bool HasDecodedAll() const { return toc_.size() == num_sections_done_; }
    129 
    130  size_t NumCompletePasses() const {
    131    return *std::min_element(decoded_passes_per_ac_group_.begin(),
    132                             decoded_passes_per_ac_group_.end());
    133  }
    134 
    135  // If enabled, ProcessSections will stop and return true when the DC
    136  // sections have been processed, instead of starting the AC sections. This
    137  // will only occur if supported (that is, flushing will produce a valid
    138  // 1/8th*1/8th resolution image). The return value of true then does not mean
    139  // all sections have been processed, use HasDecodedDC and HasDecodedAll
    140  // to check the true finished state.
    141  // Returns the progressive detail that will be effective for the frame.
    142  JxlProgressiveDetail SetPauseAtProgressive(JxlProgressiveDetail prog_detail) {
    143    bool single_section =
    144        frame_dim_.num_groups == 1 && frame_header_.passes.num_passes == 1;
    145    if (frame_header_.frame_type != kSkipProgressive &&
    146        // If there's only one group and one pass, there is no separate section
    147        // for DC and the entire full resolution image is available at once.
    148        !single_section &&
    149        // If extra channels are encoded with modular without squeeze, they
    150        // don't support DC. If the are encoded with squeeze, DC works in theory
    151        // but the implementation may not yet correctly support this for Flush.
    152        // Therefore, can't correctly pause for a progressive step if there is
    153        // an extra channel (including alpha channel)
    154        // TODO(firsching): Check if this is still the case.
    155        decoded_->metadata()->extra_channel_info.empty() &&
    156        // DC is not guaranteed to be available in modular mode and may be a
    157        // black image. If squeeze is used, it may be available depending on the
    158        // current implementation.
    159        // TODO(lode): do return DC if it's known that flushing at this point
    160        // will produce a valid 1/8th downscaled image with modular encoding.
    161        frame_header_.encoding == FrameEncoding::kVarDCT) {
    162      progressive_detail_ = prog_detail;
    163    } else {
    164      progressive_detail_ = JxlProgressiveDetail::kFrames;
    165    }
    166    if (progressive_detail_ >= JxlProgressiveDetail::kPasses) {
    167      for (size_t i = 1; i < frame_header_.passes.num_passes; ++i) {
    168        passes_to_pause_.push_back(i);
    169      }
    170    } else if (progressive_detail_ >= JxlProgressiveDetail::kLastPasses) {
    171      for (size_t i = 0; i < frame_header_.passes.num_downsample; ++i) {
    172        passes_to_pause_.push_back(frame_header_.passes.last_pass[i] + 1);
    173      }
    174      // The format does not guarantee that these values are sorted.
    175      std::sort(passes_to_pause_.begin(), passes_to_pause_.end());
    176    }
    177    return progressive_detail_;
    178  }
    179 
    180  size_t NextNumPassesToPause() const {
    181    auto it = std::upper_bound(passes_to_pause_.begin(), passes_to_pause_.end(),
    182                               NumCompletePasses());
    183    return (it != passes_to_pause_.end() ? *it
    184                                         : std::numeric_limits<size_t>::max());
    185  }
    186 
    187  // Sets the pixel callback or image buffer where the pixels will be decoded.
    188  //
    189  // @param undo_orientation: if true, indicates the frame decoder should apply
    190  // the exif orientation to bring the image to the intended display
    191  // orientation.
    192  void SetImageOutput(const PixelCallback& pixel_callback, void* image_buffer,
    193                      size_t image_buffer_size, size_t xsize, size_t ysize,
    194                      JxlPixelFormat format, size_t bits_per_sample,
    195                      bool unpremul_alpha, bool undo_orientation) const {
    196    dec_state_->width = xsize;
    197    dec_state_->height = ysize;
    198    dec_state_->main_output.format = format;
    199    dec_state_->main_output.bits_per_sample = bits_per_sample;
    200    dec_state_->main_output.callback = pixel_callback;
    201    dec_state_->main_output.buffer = image_buffer;
    202    dec_state_->main_output.buffer_size = image_buffer_size;
    203    dec_state_->main_output.stride = GetStride(xsize, format);
    204    const jxl::ExtraChannelInfo* alpha =
    205        decoded_->metadata()->Find(jxl::ExtraChannel::kAlpha);
    206    if (alpha && alpha->alpha_associated && unpremul_alpha) {
    207      dec_state_->unpremul_alpha = true;
    208    }
    209    if (undo_orientation) {
    210      dec_state_->undo_orientation = decoded_->metadata()->GetOrientation();
    211      if (static_cast<int>(dec_state_->undo_orientation) > 4) {
    212        std::swap(dec_state_->width, dec_state_->height);
    213      }
    214    }
    215    dec_state_->extra_output.clear();
    216 #if !JXL_HIGH_PRECISION
    217    if (dec_state_->main_output.buffer &&
    218        (format.data_type == JXL_TYPE_UINT8) && (format.num_channels >= 3) &&
    219        !dec_state_->unpremul_alpha &&
    220        (dec_state_->undo_orientation == Orientation::kIdentity) &&
    221        decoded_->metadata()->xyb_encoded &&
    222        dec_state_->output_encoding_info.color_encoding.IsSRGB() &&
    223        dec_state_->output_encoding_info.all_default_opsin &&
    224        (dec_state_->output_encoding_info.desired_intensity_target ==
    225         dec_state_->output_encoding_info.orig_intensity_target) &&
    226        HasFastXYBTosRGB8() && frame_header_.needs_color_transform()) {
    227      dec_state_->fast_xyb_srgb8_conversion = true;
    228    }
    229 #endif
    230  }
    231 
    232  void AddExtraChannelOutput(void* buffer, size_t buffer_size, size_t xsize,
    233                             JxlPixelFormat format, size_t bits_per_sample) {
    234    ImageOutput out;
    235    out.format = format;
    236    out.bits_per_sample = bits_per_sample;
    237    out.buffer = buffer;
    238    out.buffer_size = buffer_size;
    239    out.stride = GetStride(xsize, format);
    240    dec_state_->extra_output.push_back(out);
    241  }
    242 
    243 private:
    244  Status ProcessDCGlobal(BitReader* br);
    245  Status ProcessDCGroup(size_t dc_group_id, BitReader* br);
    246  Status FinalizeDC();
    247  Status AllocateOutput();
    248  Status ProcessACGlobal(BitReader* br);
    249  Status ProcessACGroup(size_t ac_group_id, BitReader* JXL_RESTRICT* br,
    250                        size_t num_passes, size_t thread, bool force_draw,
    251                        bool dc_only);
    252  void MarkSections(const SectionInfo* sections, size_t num,
    253                    const SectionStatus* section_status);
    254 
    255  // Allocates storage for parallel decoding using up to `num_threads` threads
    256  // of up to `num_tasks` tasks. The value of `thread` passed to
    257  // `GetStorageLocation` must be smaller than the `num_threads` value passed
    258  // here. The value of `task` passed to `GetStorageLocation` must be smaller
    259  // than the value of `num_tasks` passed here.
    260  Status PrepareStorage(size_t num_threads, size_t num_tasks) {
    261    size_t storage_size = std::min(num_threads, num_tasks);
    262    if (storage_size > group_dec_caches_.size()) {
    263      group_dec_caches_.resize(storage_size);
    264    }
    265    use_task_id_ = num_threads > num_tasks;
    266    bool use_noise = (frame_header_.flags & FrameHeader::kNoise) != 0;
    267    bool use_group_ids =
    268        (modular_frame_decoder_.UsesFullImage() &&
    269         (frame_header_.encoding == FrameEncoding::kVarDCT || use_noise));
    270    if (dec_state_->render_pipeline) {
    271      JXL_RETURN_IF_ERROR(dec_state_->render_pipeline->PrepareForThreads(
    272          storage_size, use_group_ids));
    273    }
    274    return true;
    275  }
    276 
    277  size_t GetStorageLocation(size_t thread, size_t task) const {
    278    if (use_task_id_) return task;
    279    return thread;
    280  }
    281 
    282  static size_t BytesPerChannel(JxlDataType data_type) {
    283    return (data_type == JXL_TYPE_UINT8   ? 1u
    284            : data_type == JXL_TYPE_FLOAT ? 4u
    285                                          : 2u);
    286  }
    287 
    288  static size_t GetStride(const size_t xsize, JxlPixelFormat format) {
    289    size_t stride =
    290        (xsize * BytesPerChannel(format.data_type) * format.num_channels);
    291    if (format.align > 1) {
    292      stride = (jxl::DivCeil(stride, format.align) * format.align);
    293    }
    294    return stride;
    295  }
    296 
    297  bool HasDcGroupToDecode() const {
    298    return std::any_of(decoded_dc_groups_.cbegin(), decoded_dc_groups_.cend(),
    299                       [](uint8_t ready) { return ready == 0; });
    300  }
    301 
    302  PassesDecoderState* dec_state_;
    303  ThreadPool* pool_;
    304  std::vector<TocEntry> toc_;
    305  uint64_t section_sizes_sum_;
    306  // TODO(veluca): figure out the duplication between these and dec_state_.
    307  FrameHeader frame_header_;
    308  FrameDimensions frame_dim_;
    309  ImageBundle* decoded_;
    310  ModularFrameDecoder modular_frame_decoder_;
    311  bool render_spotcolors_ = true;
    312  bool coalescing_ = true;
    313 
    314  std::vector<uint8_t> processed_section_;
    315  std::vector<uint8_t> decoded_passes_per_ac_group_;
    316  std::vector<uint8_t> decoded_dc_groups_;
    317  bool decoded_dc_global_;
    318  bool decoded_ac_global_;
    319  bool HasEverything() const;
    320  bool finalized_dc_ = true;
    321  size_t num_sections_done_ = 0;
    322  bool is_finalized_ = true;
    323  bool allocated_ = false;
    324 
    325  std::vector<GroupDecCache> group_dec_caches_;
    326 
    327  // Whether or not the task id should be used for storage indexing, instead of
    328  // the thread id.
    329  bool use_task_id_ = false;
    330 
    331  // Testing setting: whether or not to use the slow rendering pipeline.
    332  bool use_slow_rendering_pipeline_;
    333 
    334  JxlProgressiveDetail progressive_detail_ = kFrames;
    335  // Number of completed passes where section decoding should pause.
    336  // Used for progressive details at least kLastPasses.
    337  std::vector<int> passes_to_pause_;
    338 };
    339 
    340 }  // namespace jxl
    341 
    342 #endif  // LIB_JXL_DEC_FRAME_H_