The Tor Browser: media/libjpeg/jcmarker.c@b8a032363ba2 (annotated)

media/libjpeg/jcmarker.c@b8a032363ba2 (annotated)

media/libjpeg/jcmarker.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * jcmarker.c
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1998, Thomas G. Lane.
  * Modified 2003-2010 by Guido Vollbeding.
  * libjpeg-turbo Modifications:
  * Copyright (C) 2010, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains routines to write JPEG datastream markers.
  */
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
 #include "jpegcomp.h"
 typedef enum {			/* JPEG marker codes */
   M_SOF0  = 0xc0,
   M_SOF1  = 0xc1,
   M_SOF2  = 0xc2,
   M_SOF3  = 0xc3,
   M_SOF5  = 0xc5,
   M_SOF6  = 0xc6,
   M_SOF7  = 0xc7,
   M_JPG   = 0xc8,
   M_SOF9  = 0xc9,
   M_SOF10 = 0xca,
   M_SOF11 = 0xcb,
   M_SOF13 = 0xcd,
   M_SOF14 = 0xce,
   M_SOF15 = 0xcf,
   M_DHT   = 0xc4,
   M_DAC   = 0xcc,
   M_RST0  = 0xd0,
   M_RST1  = 0xd1,
   M_RST2  = 0xd2,
   M_RST3  = 0xd3,
   M_RST4  = 0xd4,
   M_RST5  = 0xd5,
   M_RST6  = 0xd6,
   M_RST7  = 0xd7,
   M_SOI   = 0xd8,
   M_EOI   = 0xd9,
   M_SOS   = 0xda,
   M_DQT   = 0xdb,
   M_DNL   = 0xdc,
   M_DRI   = 0xdd,
   M_DHP   = 0xde,
   M_EXP   = 0xdf,
   M_APP0  = 0xe0,
   M_APP1  = 0xe1,
   M_APP2  = 0xe2,
   M_APP3  = 0xe3,
   M_APP4  = 0xe4,
   M_APP5  = 0xe5,
   M_APP6  = 0xe6,
   M_APP7  = 0xe7,
   M_APP8  = 0xe8,
   M_APP9  = 0xe9,
   M_APP10 = 0xea,
   M_APP11 = 0xeb,
   M_APP12 = 0xec,
   M_APP13 = 0xed,
   M_APP14 = 0xee,
   M_APP15 = 0xef,
   M_JPG0  = 0xf0,
   M_JPG13 = 0xfd,
   M_COM   = 0xfe,
   M_TEM   = 0x01,
   M_ERROR = 0x100
 } JPEG_MARKER;
 /* Private state */
 typedef struct {
   struct jpeg_marker_writer pub; /* public fields */
   unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
 } my_marker_writer;
 typedef my_marker_writer * my_marker_ptr;
 /*
  * Basic output routines.
  *
  * Note that we do not support suspension while writing a marker.
  * Therefore, an application using suspension must ensure that there is
  * enough buffer space for the initial markers (typ. 600-700 bytes) before
  * calling jpeg_start_compress, and enough space to write the trailing EOI
  * (a few bytes) before calling jpeg_finish_compress.  Multipass compression
  * modes are not supported at all with suspension, so those two are the only
  * points where markers will be written.
  */
 LOCAL(void)
 emit_byte (j_compress_ptr cinfo, int val)
 /* Emit a byte */
 {
   struct jpeg_destination_mgr * dest = cinfo->dest;
   *(dest->next_output_byte)++ = (JOCTET) val;
   if (--dest->free_in_buffer == 0) {
     if (! (*dest->empty_output_buffer) (cinfo))
       ERREXIT(cinfo, JERR_CANT_SUSPEND);
   }
 }
 LOCAL(void)
 emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
 /* Emit a marker code */
 {
   emit_byte(cinfo, 0xFF);
   emit_byte(cinfo, (int) mark);
 }
 LOCAL(void)
 emit_2bytes (j_compress_ptr cinfo, int value)
 /* Emit a 2-byte integer; these are always MSB first in JPEG files */
 {
   emit_byte(cinfo, (value >> 8) & 0xFF);
   emit_byte(cinfo, value & 0xFF);
 }
 /*
  * Routines to write specific marker types.
  */
 LOCAL(int)
 emit_dqt (j_compress_ptr cinfo, int index)
 /* Emit a DQT marker */
 /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
 {
   JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
   int prec;
   int i;
   if (qtbl == NULL)
     ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
   prec = 0;
   for (i = 0; i < DCTSIZE2; i++) {
     if (qtbl->quantval[i] > 255)
       prec = 1;
   }
   if (! qtbl->sent_table) {
     emit_marker(cinfo, M_DQT);
     emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
     emit_byte(cinfo, index + (prec<<4));
     for (i = 0; i < DCTSIZE2; i++) {
       /* The table entries must be emitted in zigzag order. */
       unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
       if (prec)
 	emit_byte(cinfo, (int) (qval >> 8));
       emit_byte(cinfo, (int) (qval & 0xFF));
     }
     qtbl->sent_table = TRUE;
   }
   return prec;
 }
 LOCAL(void)
 emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
 /* Emit a DHT marker */
 {
   JHUFF_TBL * htbl;
   int length, i;
   if (is_ac) {
     htbl = cinfo->ac_huff_tbl_ptrs[index];
     index += 0x10;		/* output index has AC bit set */
   } else {
     htbl = cinfo->dc_huff_tbl_ptrs[index];
   }
   if (htbl == NULL)
     ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
   if (! htbl->sent_table) {
     emit_marker(cinfo, M_DHT);
     length = 0;
     for (i = 1; i <= 16; i++)
       length += htbl->bits[i];
     emit_2bytes(cinfo, length + 2 + 1 + 16);
     emit_byte(cinfo, index);
     for (i = 1; i <= 16; i++)
       emit_byte(cinfo, htbl->bits[i]);
     for (i = 0; i < length; i++)
       emit_byte(cinfo, htbl->huffval[i]);
     htbl->sent_table = TRUE;
   }
 }
 LOCAL(void)
 emit_dac (j_compress_ptr cinfo)
 /* Emit a DAC marker */
 /* Since the useful info is so small, we want to emit all the tables in */
 /* one DAC marker.  Therefore this routine does its own scan of the table. */
 {
 #ifdef C_ARITH_CODING_SUPPORTED
   char dc_in_use[NUM_ARITH_TBLS];
   char ac_in_use[NUM_ARITH_TBLS];
   int length, i;
   jpeg_component_info *compptr;
   for (i = 0; i < NUM_ARITH_TBLS; i++)
     dc_in_use[i] = ac_in_use[i] = 0;
   for (i = 0; i < cinfo->comps_in_scan; i++) {
     compptr = cinfo->cur_comp_info[i];
     /* DC needs no table for refinement scan */
     if (cinfo->Ss == 0 && cinfo->Ah == 0)
       dc_in_use[compptr->dc_tbl_no] = 1;
     /* AC needs no table when not present */
     if (cinfo->Se)
       ac_in_use[compptr->ac_tbl_no] = 1;
   }
   length = 0;
   for (i = 0; i < NUM_ARITH_TBLS; i++)
     length += dc_in_use[i] + ac_in_use[i];
   if (length) {
     emit_marker(cinfo, M_DAC);
     emit_2bytes(cinfo, length*2 + 2);
     for (i = 0; i < NUM_ARITH_TBLS; i++) {
       if (dc_in_use[i]) {
 	emit_byte(cinfo, i);
 	emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
       }
       if (ac_in_use[i]) {
 	emit_byte(cinfo, i + 0x10);
 	emit_byte(cinfo, cinfo->arith_ac_K[i]);
       }
     }
   }
 #endif /* C_ARITH_CODING_SUPPORTED */
 }
 LOCAL(void)
 emit_dri (j_compress_ptr cinfo)
 /* Emit a DRI marker */
 {
   emit_marker(cinfo, M_DRI);
   emit_2bytes(cinfo, 4);	/* fixed length */
   emit_2bytes(cinfo, (int) cinfo->restart_interval);
 }
 LOCAL(void)
 emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
 /* Emit a SOF marker */
 {
   int ci;
   jpeg_component_info *compptr;
   emit_marker(cinfo, code);
   emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
   /* Make sure image isn't bigger than SOF field can handle */
   if ((long) cinfo->_jpeg_height > 65535L ||
       (long) cinfo->_jpeg_width > 65535L)
     ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
   emit_byte(cinfo, cinfo->data_precision);
   emit_2bytes(cinfo, (int) cinfo->_jpeg_height);
   emit_2bytes(cinfo, (int) cinfo->_jpeg_width);
   emit_byte(cinfo, cinfo->num_components);
   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
        ci++, compptr++) {
     emit_byte(cinfo, compptr->component_id);
     emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
     emit_byte(cinfo, compptr->quant_tbl_no);
   }
 }
 LOCAL(void)
 emit_sos (j_compress_ptr cinfo)
 /* Emit a SOS marker */
 {
   int i, td, ta;
   jpeg_component_info *compptr;
   emit_marker(cinfo, M_SOS);
   emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
   emit_byte(cinfo, cinfo->comps_in_scan);
   for (i = 0; i < cinfo->comps_in_scan; i++) {
     compptr = cinfo->cur_comp_info[i];
     emit_byte(cinfo, compptr->component_id);
     /* We emit 0 for unused field(s); this is recommended by the P&M text
      * but does not seem to be specified in the standard.
      */
     /* DC needs no table for refinement scan */
     td = cinfo->Ss == 0 && cinfo->Ah == 0 ? compptr->dc_tbl_no : 0;
     /* AC needs no table when not present */
     ta = cinfo->Se ? compptr->ac_tbl_no : 0;
     emit_byte(cinfo, (td << 4) + ta);
   }
   emit_byte(cinfo, cinfo->Ss);
   emit_byte(cinfo, cinfo->Se);
   emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
 }
 LOCAL(void)
 emit_jfif_app0 (j_compress_ptr cinfo)
 /* Emit a JFIF-compliant APP0 marker */
 {
   /*
    * Length of APP0 block	(2 bytes)
    * Block ID			(4 bytes - ASCII "JFIF")
    * Zero byte			(1 byte to terminate the ID string)
    * Version Major, Minor	(2 bytes - major first)
    * Units			(1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
    * Xdpu			(2 bytes - dots per unit horizontal)
    * Ydpu			(2 bytes - dots per unit vertical)
    * Thumbnail X size		(1 byte)
    * Thumbnail Y size		(1 byte)
    */
   emit_marker(cinfo, M_APP0);
   emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
   emit_byte(cinfo, 0x4A);	/* Identifier: ASCII "JFIF" */
   emit_byte(cinfo, 0x46);
   emit_byte(cinfo, 0x49);
   emit_byte(cinfo, 0x46);
   emit_byte(cinfo, 0);
   emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
   emit_byte(cinfo, cinfo->JFIF_minor_version);
   emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
   emit_2bytes(cinfo, (int) cinfo->X_density);
   emit_2bytes(cinfo, (int) cinfo->Y_density);
   emit_byte(cinfo, 0);		/* No thumbnail image */
   emit_byte(cinfo, 0);
 }
 LOCAL(void)
 emit_adobe_app14 (j_compress_ptr cinfo)
 /* Emit an Adobe APP14 marker */
 {
   /*
    * Length of APP14 block	(2 bytes)
    * Block ID			(5 bytes - ASCII "Adobe")
    * Version Number		(2 bytes - currently 100)
    * Flags0			(2 bytes - currently 0)
    * Flags1			(2 bytes - currently 0)
    * Color transform		(1 byte)
    *
    * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
    * now in circulation seem to use Version = 100, so that's what we write.
    *
    * We write the color transform byte as 1 if the JPEG color space is
    * YCbCr, 2 if it's YCCK, 0 otherwise.  Adobe's definition has to do with
    * whether the encoder performed a transformation, which is pretty useless.
    */
   emit_marker(cinfo, M_APP14);
   emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
   emit_byte(cinfo, 0x41);	/* Identifier: ASCII "Adobe" */
   emit_byte(cinfo, 0x64);
   emit_byte(cinfo, 0x6F);
   emit_byte(cinfo, 0x62);
   emit_byte(cinfo, 0x65);
   emit_2bytes(cinfo, 100);	/* Version */
   emit_2bytes(cinfo, 0);	/* Flags0 */
   emit_2bytes(cinfo, 0);	/* Flags1 */
   switch (cinfo->jpeg_color_space) {
   case JCS_YCbCr:
     emit_byte(cinfo, 1);	/* Color transform = 1 */
     break;
   case JCS_YCCK:
     emit_byte(cinfo, 2);	/* Color transform = 2 */
     break;
   default:
     emit_byte(cinfo, 0);	/* Color transform = 0 */
     break;
   }
 }
 /*
  * These routines allow writing an arbitrary marker with parameters.
  * The only intended use is to emit COM or APPn markers after calling
  * write_file_header and before calling write_frame_header.
  * Other uses are not guaranteed to produce desirable results.
  * Counting the parameter bytes properly is the caller's responsibility.
  */
 METHODDEF(void)
 write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
 /* Emit an arbitrary marker header */
 {
   if (datalen > (unsigned int) 65533)		/* safety check */
     ERREXIT(cinfo, JERR_BAD_LENGTH);
   emit_marker(cinfo, (JPEG_MARKER) marker);
   emit_2bytes(cinfo, (int) (datalen + 2));	/* total length */
 }
 METHODDEF(void)
 write_marker_byte (j_compress_ptr cinfo, int val)
 /* Emit one byte of marker parameters following write_marker_header */
 {
   emit_byte(cinfo, val);
 }
 /*
  * Write datastream header.
  * This consists of an SOI and optional APPn markers.
  * We recommend use of the JFIF marker, but not the Adobe marker,
  * when using YCbCr or grayscale data.  The JFIF marker should NOT
  * be used for any other JPEG colorspace.  The Adobe marker is helpful
  * to distinguish RGB, CMYK, and YCCK colorspaces.
  * Note that an application can write additional header markers after
  * jpeg_start_compress returns.
  */
 METHODDEF(void)
 write_file_header (j_compress_ptr cinfo)
 {
   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
   emit_marker(cinfo, M_SOI);	/* first the SOI */
   /* SOI is defined to reset restart interval to 0 */
   marker->last_restart_interval = 0;
   if (cinfo->write_JFIF_header)	/* next an optional JFIF APP0 */
     emit_jfif_app0(cinfo);
   if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
     emit_adobe_app14(cinfo);
 }
 /*
  * Write frame header.
  * This consists of DQT and SOFn markers.
  * Note that we do not emit the SOF until we have emitted the DQT(s).
  * This avoids compatibility problems with incorrect implementations that
  * try to error-check the quant table numbers as soon as they see the SOF.
  */
 METHODDEF(void)
 write_frame_header (j_compress_ptr cinfo)
 {
   int ci, prec;
   boolean is_baseline;
   jpeg_component_info *compptr;
   /* Emit DQT for each quantization table.
    * Note that emit_dqt() suppresses any duplicate tables.
    */
   prec = 0;
   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
        ci++, compptr++) {
     prec += emit_dqt(cinfo, compptr->quant_tbl_no);
   }
   /* now prec is nonzero iff there are any 16-bit quant tables. */
   /* Check for a non-baseline specification.
    * Note we assume that Huffman table numbers won't be changed later.
    */
   if (cinfo->arith_code || cinfo->progressive_mode ||
       cinfo->data_precision != 8) {
     is_baseline = FALSE;
   } else {
     is_baseline = TRUE;
     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 	 ci++, compptr++) {
       if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
 	is_baseline = FALSE;
     }
     if (prec && is_baseline) {
       is_baseline = FALSE;
       /* If it's baseline except for quantizer size, warn the user */
       TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
     }
   }
   /* Emit the proper SOF marker */
   if (cinfo->arith_code) {
     if (cinfo->progressive_mode)
       emit_sof(cinfo, M_SOF10); /* SOF code for progressive arithmetic */
     else
       emit_sof(cinfo, M_SOF9);  /* SOF code for sequential arithmetic */
   } else {
     if (cinfo->progressive_mode)
       emit_sof(cinfo, M_SOF2);	/* SOF code for progressive Huffman */
     else if (is_baseline)
       emit_sof(cinfo, M_SOF0);	/* SOF code for baseline implementation */
     else
       emit_sof(cinfo, M_SOF1);	/* SOF code for non-baseline Huffman file */
   }
 }
 /*
  * Write scan header.
  * This consists of DHT or DAC markers, optional DRI, and SOS.
  * Compressed data will be written following the SOS.
  */
 METHODDEF(void)
 write_scan_header (j_compress_ptr cinfo)
 {
   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
   int i;
   jpeg_component_info *compptr;
   if (cinfo->arith_code) {
     /* Emit arith conditioning info.  We may have some duplication
      * if the file has multiple scans, but it's so small it's hardly
      * worth worrying about.
      */
     emit_dac(cinfo);
   } else {
     /* Emit Huffman tables.
      * Note that emit_dht() suppresses any duplicate tables.
      */
     for (i = 0; i < cinfo->comps_in_scan; i++) {
       compptr = cinfo->cur_comp_info[i];
       /* DC needs no table for refinement scan */
       if (cinfo->Ss == 0 && cinfo->Ah == 0)
 	emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
       /* AC needs no table when not present */
       if (cinfo->Se)
 	emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
     }
   }
   /* Emit DRI if required --- note that DRI value could change for each scan.
    * We avoid wasting space with unnecessary DRIs, however.
    */
   if (cinfo->restart_interval != marker->last_restart_interval) {
     emit_dri(cinfo);
     marker->last_restart_interval = cinfo->restart_interval;
   }
   emit_sos(cinfo);
 }
 /*
  * Write datastream trailer.
  */
 METHODDEF(void)
 write_file_trailer (j_compress_ptr cinfo)
 {
   emit_marker(cinfo, M_EOI);
 }
 /*
  * Write an abbreviated table-specification datastream.
  * This consists of SOI, DQT and DHT tables, and EOI.
  * Any table that is defined and not marked sent_table = TRUE will be
  * emitted.  Note that all tables will be marked sent_table = TRUE at exit.
  */
 METHODDEF(void)
 write_tables_only (j_compress_ptr cinfo)
 {
   int i;
   emit_marker(cinfo, M_SOI);
   for (i = 0; i < NUM_QUANT_TBLS; i++) {
     if (cinfo->quant_tbl_ptrs[i] != NULL)
       (void) emit_dqt(cinfo, i);
   }
   if (! cinfo->arith_code) {
     for (i = 0; i < NUM_HUFF_TBLS; i++) {
       if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
 	emit_dht(cinfo, i, FALSE);
       if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
 	emit_dht(cinfo, i, TRUE);
     }
   }
   emit_marker(cinfo, M_EOI);
 }
 /*
  * Initialize the marker writer module.
  */
 GLOBAL(void)
 jinit_marker_writer (j_compress_ptr cinfo)
 {
   my_marker_ptr marker;
   /* Create the subobject */
   marker = (my_marker_ptr)
     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
 				SIZEOF(my_marker_writer));
   cinfo->marker = (struct jpeg_marker_writer *) marker;
   /* Initialize method pointers */
   marker->pub.write_file_header = write_file_header;
   marker->pub.write_frame_header = write_frame_header;
   marker->pub.write_scan_header = write_scan_header;
   marker->pub.write_file_trailer = write_file_trailer;
   marker->pub.write_tables_only = write_tables_only;
   marker->pub.write_marker_header = write_marker_header;
   marker->pub.write_marker_byte = write_marker_byte;
   /* Initialize private state */
   marker->last_restart_interval = 0;
 }

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media/libjpeg/jcmarker.c@b8a032363ba2 (annotated)

media/libjpeg/jcmarker.c