1 files changed, 60 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jpegli/bit_writer.cc b/third_party/jpeg-xl/lib/jpegli/bit_writer.cc
new file mode 100644
index 0000000000..9788f35b8d
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jpegli/bit_writer.cc
@@ -0,0 +1,60 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/jpegli/bit_writer.h"
+
+#include "lib/jpegli/encode_internal.h"
+
+namespace jpegli {
+
+void JpegBitWriterInit(j_compress_ptr cinfo) {
+  jpeg_comp_master* m = cinfo->master;
+  JpegBitWriter* bw = &m->bw;
+  size_t buffer_size = m->blocks_per_iMCU_row * (DCTSIZE2 * 16 + 8) + (1 << 16);
+  bw->cinfo = cinfo;
+  bw->data = Allocate<uint8_t>(cinfo, buffer_size, JPOOL_IMAGE);
+  bw->len = buffer_size;
+  bw->pos = 0;
+  bw->output_pos = 0;
+  bw->put_buffer = 0;
+  bw->free_bits = 64;
+  bw->healthy = true;
+}
+
+bool EmptyBitWriterBuffer(JpegBitWriter* bw) {
+  while (bw->output_pos < bw->pos) {
+    j_compress_ptr cinfo = bw->cinfo;
+    if (cinfo->dest->free_in_buffer == 0 &&
+        !(*cinfo->dest->empty_output_buffer)(cinfo)) {
+      return false;
+    }
+    size_t buflen = bw->pos - bw->output_pos;
+    size_t copylen = std::min<size_t>(cinfo->dest->free_in_buffer, buflen);
+    memcpy(cinfo->dest->next_output_byte, bw->data + bw->output_pos, copylen);
+    bw->output_pos += copylen;
+    cinfo->dest->free_in_buffer -= copylen;
+    cinfo->dest->next_output_byte += copylen;
+  }
+  bw->output_pos = bw->pos = 0;
+  return true;
+}
+
+void JumpToByteBoundary(JpegBitWriter* bw) {
+  size_t n_bits = bw->free_bits & 7u;
+  if (n_bits > 0) {
+    WriteBits(bw, n_bits, (1u << n_bits) - 1);
+  }
+  bw->put_buffer <<= bw->free_bits;
+  while (bw->free_bits <= 56) {
+    int c = (bw->put_buffer >> 56) & 0xFF;
+    EmitByte(bw, c);
+    bw->put_buffer <<= 8;
+    bw->free_bits += 8;
+  }
+  bw->put_buffer = 0;
+  bw->free_bits = 64;
+}
+
+}  // namespace jpegli