/*

 * Copyright (c) 2018, Mapbox

 * Author: <norman.barker at mapbox.com>

 *

 * Permission to use, copy, modify, distribute, and sell this software and

 * its documentation for any purpose is hereby granted without fee, provided

 * that (i) the above copyright notices and this permission notice appear in

 * all copies of the software and related documentation, and (ii) the names of

 * Sam Leffler and Silicon Graphics may not be used in any advertising or

 * publicity relating to the software without the specific, prior written

 * permission of Sam Leffler and Silicon Graphics.

 *

 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY

 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

 *

 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR

 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,

 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF

 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE

 * OF THIS SOFTWARE.

 */

#include "tiffiop.h"

#ifdef WEBP_SUPPORT

/*

 * TIFF Library.

 *

 * WEBP Compression Support

 *

 */

#include "webp/decode.h"

#include "webp/encode.h"

#include <stdbool.h>

#include <stdio.h>

#define LSTATE_INIT_DECODE 0x01

#define LSTATE_INIT_ENCODE 0x02

/*

 * State block for each open TIFF

 * file using WEBP compression/decompression.

 */

typedef struct

{

    uint16_t nSamples; /* number of samples per pixel */

    int read_error; /* whether a read error has occurred, and which should cause

                       further reads in the same strip/tile to be aborted */

    int lossless;   /* lossy/lossless compression */

    int lossless_exact;   /* lossless exact mode. If TRUE, R,G,B values in areas

                             with alpha = 0 will be preserved */

    int quality_level;    /* compression level */

    WebPPicture sPicture; /* WebP Picture */

    WebPConfig sEncoderConfig;  /* WebP encoder config */

    uint8_t *pBuffer;           /* buffer to hold raw data on encoding */

    unsigned int buffer_offset; /* current offset into the buffer */

    unsigned int buffer_size;

    WebPIDecoder *psDecoder;  /* WebPIDecoder */

    WebPDecBuffer sDecBuffer; /* Decoder buffer */

    int last_y;               /* Last row decoded */

    int state; /* state flags */

    TIFFVGetMethod vgetparent; /* super-class method */

    TIFFVSetMethod vsetparent; /* super-class method */

} WebPState;

#define LState(tif) ((WebPState *)(tif)->tif_data)

#define DecoderState(tif) LState(tif)

#define EncoderState(tif) LState(tif)

static int TWebPEncode(TIFF *tif, uint8_t *bp, tmsize_t cc, uint16_t s);

static int TWebPDecode(TIFF *tif, uint8_t *op, tmsize_t occ, uint16_t s);

static int TWebPDatasetWriter(const uint8_t *data, size_t data_size,

                              const WebPPicture *const picture)

{

    static const char module[] = "TWebPDatasetWriter";

    TIFF *tif = (TIFF *)(picture->custom_ptr);

    if ((tif->tif_rawcc + (tmsize_t)data_size) > tif->tif_rawdatasize)

    {

        TIFFErrorExtR(tif, module,

                      "Buffer too small by %" TIFF_SIZE_FORMAT " bytes.",

                      (size_t)((uint64_t)tif->tif_rawcc + (uint64_t)data_size -

                               (uint64_t)tif->tif_rawdatasize));

        return 0;

    }

    else

    {

        _TIFFmemcpy(tif->tif_rawcp, data, (tmsize_t)data_size);

        tif->tif_rawcc += (tmsize_t)data_size;

        tif->tif_rawcp += data_size;

        return 1;

    }

}

/*

 * Encode a chunk of pixels.

 */

static int TWebPEncode(TIFF *tif, uint8_t *bp, tmsize_t cc, uint16_t s)

{

    static const char module[] = "TWebPEncode";

    WebPState *sp = EncoderState(tif);

    (void)s;

    assert(sp != NULL);

    assert(sp->state == LSTATE_INIT_ENCODE);

    if ((uint64_t)sp->buffer_offset + (uint64_t)cc > sp->buffer_size)

    {

        TIFFErrorExtR(tif, module, "Too many bytes to be written");

        return 0;

    }

    memcpy(sp->pBuffer + sp->buffer_offset, bp, (size_t)cc);

    sp->buffer_offset += (unsigned)cc;

    return 1;

}

static int TWebPDecode(TIFF *tif, uint8_t *op, tmsize_t occ, uint16_t s)

{

    static const char module[] = "WebPDecode";

    VP8StatusCode status = VP8_STATUS_OK;

    WebPState *sp = DecoderState(tif);

    uint32_t segment_width, segment_height;

    bool decode_whole_strile = false;

    (void)s;

    assert(sp != NULL);

    assert(sp->state == LSTATE_INIT_DECODE);

    if (sp->read_error)

    {

        memset(op, 0, (size_t)occ);

        TIFFErrorExtR(tif, module,

                      "ZIPDecode: Scanline %" PRIu32 " cannot be read due to "

                      "previous error",

                      tif->tif_dir.td_row);

        return 0;

    }

    if (sp->psDecoder == NULL)

    {

        TIFFDirectory *td = &tif->tif_dir;

        uint32_t buffer_size;

        if (isTiled(tif))

        {

            segment_width = td->td_tilewidth;

            segment_height = td->td_tilelength;

        }

        else

        {

            segment_width = td->td_imagewidth;

            segment_height = td->td_imagelength - tif->tif_dir.td_row;

            if (segment_height > td->td_rowsperstrip)

                segment_height = td->td_rowsperstrip;

        }

        int webp_width, webp_height;

        if (!WebPGetInfo(tif->tif_rawcp,

                         (uint64_t)tif->tif_rawcc > UINT32_MAX

                             ? UINT32_MAX

                             : (uint32_t)tif->tif_rawcc,

                         &webp_width, &webp_height))

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(tif, module, "WebPGetInfo() failed");

            return 0;

        }

        if ((uint32_t)webp_width != segment_width ||

            (uint32_t)webp_height != segment_height)

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(

                tif, module, "WebP blob dimension is %dx%d. Expected %ux%u",

                webp_width, webp_height, segment_width, segment_height);

            return 0;

        }

#if WEBP_DECODER_ABI_VERSION >= 0x0002

        WebPDecoderConfig config;

        if (!WebPInitDecoderConfig(&config))

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(tif, module, "WebPInitDecoderConfig() failed");

            return 0;

        }

        const bool bWebPGetFeaturesOK =

            WebPGetFeatures(tif->tif_rawcp,

                            (uint64_t)tif->tif_rawcc > UINT32_MAX

                                ? UINT32_MAX

                                : (uint32_t)tif->tif_rawcc,

                            &config.input) == VP8_STATUS_OK;

        WebPFreeDecBuffer(&config.output);

        if (!bWebPGetFeaturesOK)

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(tif, module, "WebPInitDecoderConfig() failed");

            return 0;

        }

        const int webp_bands = config.input.has_alpha ? 4 : 3;

        if (webp_bands != sp->nSamples &&

            /* We accept the situation where the WebP blob has only 3 bands,

             * whereas the raster is 4 bands. This can happen when the alpha

             * channel is fully opaque, and WebP decoding works fine in that

             * situation.

             */

            !(webp_bands == 3 && sp->nSamples == 4))

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(tif, module,

                          "WebP blob band count is %d. Expected %d", webp_bands,

                          sp->nSamples);

            return 0;

        }

#endif

        buffer_size = segment_width * segment_height * sp->nSamples;

        if (occ == (tmsize_t)buffer_size)

        {

            /* If decoding the whole strip/tile, we can directly use the */

            /* output buffer */

            decode_whole_strile = true;

        }

        else if (sp->pBuffer == NULL || buffer_size > sp->buffer_size)

        {

            if (sp->pBuffer != NULL)

            {

                _TIFFfreeExt(tif, sp->pBuffer);

                sp->pBuffer = NULL;

            }

            sp->pBuffer = (uint8_t *)_TIFFmallocExt(tif, buffer_size);

            if (!sp->pBuffer)

            {

                TIFFErrorExtR(tif, module, "Cannot allocate buffer");

                memset(op, 0, (size_t)occ);

                sp->read_error = 1;

                return 0;

            }

            sp->buffer_size = buffer_size;

        }

        sp->last_y = 0;

        WebPInitDecBuffer(&sp->sDecBuffer);

        sp->sDecBuffer.is_external_memory = 1;

        sp->sDecBuffer.width = (int)segment_width;

        sp->sDecBuffer.height = (int)segment_height;

        sp->sDecBuffer.u.RGBA.rgba = decode_whole_strile ? op : sp->pBuffer;

        sp->sDecBuffer.u.RGBA.stride = (int)(segment_width * sp->nSamples);

        sp->sDecBuffer.u.RGBA.size = buffer_size;

        if (sp->nSamples > 3)

        {

            sp->sDecBuffer.colorspace = MODE_RGBA;

        }

        else

        {

            sp->sDecBuffer.colorspace = MODE_RGB;

        }

        sp->psDecoder = WebPINewDecoder(&sp->sDecBuffer);

        if (sp->psDecoder == NULL)

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(tif, module, "Unable to allocate WebP decoder.");

            return 0;

        }

    }

    if (occ % sp->sDecBuffer.u.RGBA.stride)

    {

        // read_error not set here as this is a usage issue that can be

        // recovered in a following call.

        memset(op, 0, (size_t)occ);

        /* Do not set read_error as could potentially be recovered */

        TIFFErrorExtR(tif, module, "Fractional scanlines cannot be read");

        return 0;

    }

    status = WebPIAppend(sp->psDecoder, tif->tif_rawcp, (size_t)tif->tif_rawcc);

    if (status != VP8_STATUS_OK && status != VP8_STATUS_SUSPENDED)

    {

        if (status == VP8_STATUS_INVALID_PARAM)

        {

            TIFFErrorExtR(tif, module, "Invalid parameter used.");

        }

        else if (status == VP8_STATUS_OUT_OF_MEMORY)

        {

            TIFFErrorExtR(tif, module, "Out of memory.");

        }

        else

        {

            TIFFErrorExtR(tif, module, "Unrecognized error.");

        }

        memset(op, 0, (size_t)occ);

        sp->read_error = 1;

        return 0;

    }

    else

    {

        int current_y, stride;

        uint8_t *buf;

        /* Returns the RGB/A image decoded so far */

        buf = WebPIDecGetRGB(sp->psDecoder, &current_y, NULL, NULL, &stride);

        if ((buf != NULL) &&

            (occ <= (tmsize_t)stride * (current_y - sp->last_y)))

        {

            const int numberOfExpectedLines =

                (int)(occ / sp->sDecBuffer.u.RGBA.stride);

            if (decode_whole_strile)

            {

                if (current_y != numberOfExpectedLines)

                {

                    memset(op, 0, (size_t)occ);

                    sp->read_error = 1;

                    TIFFErrorExtR(tif, module,

                                  "Unable to decode WebP data: less lines than "

                                  "expected.");

                    return 0;

                }

            }

            else

            {

                memcpy(op, buf + (sp->last_y * stride), (size_t)occ);

            }

            tif->tif_rawcp += tif->tif_rawcc;

            tif->tif_rawcc = 0;

            sp->last_y += numberOfExpectedLines;

            if (decode_whole_strile)

            {

                /* We can now free the decoder as we're completely done */

                if (sp->psDecoder != NULL)

                {

                    WebPIDelete(sp->psDecoder);

                    WebPFreeDecBuffer(&sp->sDecBuffer);

                    sp->psDecoder = NULL;

                }

            }

            return 1;

        }

        else

        {

            memset(op, 0, (size_t)occ);

            sp->read_error = 1;

            TIFFErrorExtR(tif, module, "Unable to decode WebP data.");

            return 0;

        }

    }

}

static int TWebPFixupTags(TIFF *tif)

{

    (void)tif;

    if (tif->tif_dir.td_planarconfig != PLANARCONFIG_CONTIG)

    {

        static const char module[] = "TWebPFixupTags";

        TIFFErrorExtR(tif, module,

                      "TIFF WEBP requires data to be stored contiguously in "

                      "RGB e.g. RGBRGBRGB "

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

                      "or RGBARGBARGBA"

#endif

        );

        return 0;

    }

    return 1;

}

static int TWebPSetupDecode(TIFF *tif)

{

    static const char module[] = "WebPSetupDecode";

    uint16_t nBitsPerSample = tif->tif_dir.td_bitspersample;

    uint16_t sampleFormat = tif->tif_dir.td_sampleformat;

    WebPState *sp = DecoderState(tif);

    assert(sp != NULL);

    sp->nSamples = tif->tif_dir.td_samplesperpixel;

    /* check band count */

    if (sp->nSamples != 3

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

        && sp->nSamples != 4

#endif

    )

    {

        TIFFErrorExtR(tif, module,

                      "WEBP driver doesn't support %d bands. Must be 3 (RGB) "

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

                      "or 4 (RGBA) "

#endif

                      "bands.",

                      sp->nSamples);

        return 0;

    }

    /* check bits per sample and data type */

    if ((nBitsPerSample != 8) && (sampleFormat != 1))

    {

        TIFFErrorExtR(tif, module, "WEBP driver requires 8 bit unsigned data");

        return 0;

    }

    /* if we were last encoding, terminate this mode */

    if (sp->state & LSTATE_INIT_ENCODE)

    {

        WebPPictureFree(&sp->sPicture);

        if (sp->pBuffer != NULL)

        {

            _TIFFfreeExt(tif, sp->pBuffer);

            sp->pBuffer = NULL;

        }

        sp->buffer_offset = 0;

        sp->state = 0;

    }

    sp->state |= LSTATE_INIT_DECODE;

    return 1;

}

/*

 * Setup state for decoding a strip.

 */

static int TWebPPreDecode(TIFF *tif, uint16_t s)

{

    static const char module[] = "TWebPPreDecode";

    uint32_t segment_width, segment_height;

    WebPState *sp = DecoderState(tif);

    TIFFDirectory *td = &tif->tif_dir;

    (void)s;

    assert(sp != NULL);

    if (isTiled(tif))

    {

        segment_width = td->td_tilewidth;

        segment_height = td->td_tilelength;

    }

    else

    {

        segment_width = td->td_imagewidth;

        segment_height = td->td_imagelength - tif->tif_dir.td_row;

        if (segment_height > td->td_rowsperstrip)

            segment_height = td->td_rowsperstrip;

    }

    if (segment_width > 16383 || segment_height > 16383)

    {

        TIFFErrorExtR(tif, module,

                      "WEBP maximum image dimensions are 16383 x 16383.");

        return 0;

    }

    if ((sp->state & LSTATE_INIT_DECODE) == 0)

        tif->tif_setupdecode(tif);

    if (sp->psDecoder != NULL)

    {

        WebPIDelete(sp->psDecoder);

        WebPFreeDecBuffer(&sp->sDecBuffer);

        sp->psDecoder = NULL;

    }

    sp->read_error = 0;

    return 1;

}

static int TWebPSetupEncode(TIFF *tif)

{

    static const char module[] = "WebPSetupEncode";

    uint16_t nBitsPerSample = tif->tif_dir.td_bitspersample;

    uint16_t sampleFormat = tif->tif_dir.td_sampleformat;

    WebPState *sp = EncoderState(tif);

    assert(sp != NULL);

    sp->nSamples = tif->tif_dir.td_samplesperpixel;

    /* check band count */

    if (sp->nSamples != 3

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

        && sp->nSamples != 4

#endif

    )

    {

        TIFFErrorExtR(tif, module,

                      "WEBP driver doesn't support %d bands. Must be 3 (RGB) "

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

                      "or 4 (RGBA) "

#endif

                      "bands.",

                      sp->nSamples);

        return 0;

    }

    /* check bits per sample and data type */

    if ((nBitsPerSample != 8) || (sampleFormat != SAMPLEFORMAT_UINT))

    {

        TIFFErrorExtR(tif, module, "WEBP driver requires 8 bit unsigned data");

        return 0;

    }

    if (sp->state & LSTATE_INIT_DECODE)

    {

        WebPIDelete(sp->psDecoder);

        WebPFreeDecBuffer(&sp->sDecBuffer);

        sp->psDecoder = NULL;

        sp->last_y = 0;

        sp->state = 0;

    }

    sp->state |= LSTATE_INIT_ENCODE;

    if (!WebPPictureInit(&sp->sPicture))

    {

        TIFFErrorExtR(tif, module, "Error initializing WebP picture.");

        return 0;

    }

    if (!WebPConfigInitInternal(&sp->sEncoderConfig, WEBP_PRESET_DEFAULT,

                                (float)sp->quality_level,

                                WEBP_ENCODER_ABI_VERSION))

    {

        TIFFErrorExtR(tif, module,

                      "Error creating WebP encoder configuration.");

        return 0;

    }

// WebPConfigInitInternal above sets lossless to false

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

    sp->sEncoderConfig.lossless = sp->lossless;

    if (sp->lossless)

    {

        sp->sPicture.use_argb = 1;

#if WEBP_ENCODER_ABI_VERSION >= 0x0209

        sp->sEncoderConfig.exact = sp->lossless_exact;

#endif

    }

#endif

    if (!WebPValidateConfig(&sp->sEncoderConfig))

    {

        TIFFErrorExtR(tif, module, "Error with WebP encoder configuration.");

        return 0;

    }

    return 1;

}

/*

 * Reset encoding state at the start of a strip.

 */

static int TWebPPreEncode(TIFF *tif, uint16_t s)

{

    static const char module[] = "TWebPPreEncode";

    uint32_t segment_width, segment_height;

    WebPState *sp = EncoderState(tif);

    TIFFDirectory *td = &tif->tif_dir;

    (void)s;

    assert(sp != NULL);

    if (sp->state != LSTATE_INIT_ENCODE)

        tif->tif_setupencode(tif);

    /*

     * Set encoding parameters for this strip/tile.

     */

    if (isTiled(tif))

    {

        segment_width = td->td_tilewidth;

        segment_height = td->td_tilelength;

    }

    else

    {

        segment_width = td->td_imagewidth;

        segment_height = td->td_imagelength - tif->tif_dir.td_row;

        if (segment_height > td->td_rowsperstrip)

            segment_height = td->td_rowsperstrip;

    }

    if (segment_width > 16383 || segment_height > 16383)

    {

        TIFFErrorExtR(tif, module,

                      "WEBP maximum image dimensions are 16383 x 16383.");

        return 0;

    }

    /* set up buffer for raw data */

    /* given above check and that nSamples <= 4, buffer_size is <= 1 GB */

    sp->buffer_size = segment_width * segment_height * sp->nSamples;

    if (sp->pBuffer != NULL)

    {

        _TIFFfreeExt(tif, sp->pBuffer);

        sp->pBuffer = NULL;

    }

    sp->pBuffer = (uint8_t *)_TIFFmallocExt(tif, sp->buffer_size);

    if (!sp->pBuffer)

    {

        TIFFErrorExtR(tif, module, "Cannot allocate buffer");

        return 0;

    }

    sp->buffer_offset = 0;

    sp->sPicture.width = (int)segment_width;

    sp->sPicture.height = (int)segment_height;

    sp->sPicture.writer = TWebPDatasetWriter;

    sp->sPicture.custom_ptr = tif;

    return 1;

}

/*

 * Finish off an encoded strip by flushing it.

 */

static int TWebPPostEncode(TIFF *tif)

{

    static const char module[] = "WebPPostEncode";

    int64_t stride;

    WebPState *sp = EncoderState(tif);

    assert(sp != NULL);

    assert(sp->state == LSTATE_INIT_ENCODE);

    stride = (int64_t)sp->sPicture.width * sp->nSamples;

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

    if (sp->nSamples == 4)

    {

        if (!WebPPictureImportRGBA(&sp->sPicture, sp->pBuffer, (int)stride))

        {

            TIFFErrorExtR(tif, module, "WebPPictureImportRGBA() failed");

            return 0;

        }

    }

    else

#endif

        if (!WebPPictureImportRGB(&sp->sPicture, sp->pBuffer, (int)stride))

    {

        TIFFErrorExtR(tif, module, "WebPPictureImportRGB() failed");

        return 0;

    }

    if (!WebPEncode(&sp->sEncoderConfig, &sp->sPicture))

    {

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

        const char *pszErrorMsg = NULL;

        switch (sp->sPicture.error_code)

        {

            case VP8_ENC_ERROR_OUT_OF_MEMORY:

                pszErrorMsg = "Out of memory";

                break;

            case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:

                pszErrorMsg = "Out of memory while flushing bits";

                break;

            case VP8_ENC_ERROR_NULL_PARAMETER:

                pszErrorMsg = "A pointer parameter is NULL";

                break;

            case VP8_ENC_ERROR_INVALID_CONFIGURATION:

                pszErrorMsg = "Configuration is invalid";

                break;

            case VP8_ENC_ERROR_BAD_DIMENSION:

                pszErrorMsg = "Picture has invalid width/height";

                break;

            case VP8_ENC_ERROR_PARTITION0_OVERFLOW:

                pszErrorMsg = "Partition is bigger than 512k. Try using less "

                              "SEGMENTS, or increase PARTITION_LIMIT value";

                break;

            case VP8_ENC_ERROR_PARTITION_OVERFLOW:

                pszErrorMsg = "Partition is bigger than 16M";

                break;

            case VP8_ENC_ERROR_BAD_WRITE:

                pszErrorMsg = "Error while fludshing bytes";

                break;

            case VP8_ENC_ERROR_FILE_TOO_BIG:

                pszErrorMsg = "File is bigger than 4G";

                break;

            case VP8_ENC_ERROR_USER_ABORT:

                pszErrorMsg = "User interrupted";

                break;

            case VP8_ENC_OK:

            case VP8_ENC_ERROR_LAST:

            default:

                TIFFErrorExtR(tif, module,

                              "WebPEncode returned an unknown error code: %u",

                              sp->sPicture.error_code);

                pszErrorMsg = "Unknown WebP error type.";

                break;

        }

        TIFFErrorExtR(tif, module, "WebPEncode() failed : %s", pszErrorMsg);

#else

        TIFFErrorExtR(tif, module, "Error in WebPEncode()");

#endif

        return 0;

    }

    sp->sPicture.custom_ptr = NULL;

    if (!TIFFFlushData1(tif))

    {

        TIFFErrorExtR(tif, module, "Error flushing TIFF WebP encoder.");

        return 0;

    }

    return 1;

}

static void TWebPCleanup(TIFF *tif)

{

    WebPState *sp = LState(tif);

    assert(sp != 0);

    tif->tif_tagmethods.vgetfield = sp->vgetparent;

    tif->tif_tagmethods.vsetfield = sp->vsetparent;

    if (sp->state & LSTATE_INIT_ENCODE)

    {

        WebPPictureFree(&sp->sPicture);

    }

    if (sp->psDecoder != NULL)

    {

        WebPIDelete(sp->psDecoder);

        WebPFreeDecBuffer(&sp->sDecBuffer);

        sp->psDecoder = NULL;

        sp->last_y = 0;

    }

    if (sp->pBuffer != NULL)

    {

        _TIFFfreeExt(tif, sp->pBuffer);

        sp->pBuffer = NULL;

    }

    _TIFFfreeExt(tif, tif->tif_data);

    tif->tif_data = NULL;

    _TIFFSetDefaultCompressionState(tif);

}

static int TWebPVSetField(TIFF *tif, uint32_t tag, va_list ap)

{

    static const char module[] = "WebPVSetField";

    WebPState *sp = LState(tif);

    switch (tag)

    {

        case TIFFTAG_WEBP_LEVEL:

            sp->quality_level = (int)va_arg(ap, int);

            if (sp->quality_level <= 0 || sp->quality_level > 100)

            {

                TIFFWarningExtR(tif, module,

                                "WEBP_LEVEL should be between 1 and 100");

            }

            return 1;

        case TIFFTAG_WEBP_LOSSLESS:

#if WEBP_ENCODER_ABI_VERSION >= 0x0100

            sp->lossless = va_arg(ap, int);

            if (sp->lossless)

            {

                sp->quality_level = 100;

            }

            return 1;

#else

            TIFFErrorExtR(

                tif, module,

                "Need to upgrade WEBP driver, this version doesn't support "

                "lossless compression.");

            return 0;

#endif

        case TIFFTAG_WEBP_LOSSLESS_EXACT:

#if WEBP_ENCODER_ABI_VERSION >= 0x0209

            sp->lossless_exact = va_arg(ap, int);

            return 1;

#else

            TIFFErrorExtR(

                tif, module,

                "Need to upgrade WEBP driver, this version doesn't support "

                "lossless compression.");

            return 0;

#endif

        default:

            return (*sp->vsetparent)(tif, tag, ap);

    }

    /*NOTREACHED*/

}

static int TWebPVGetField(TIFF *tif, uint32_t tag, va_list ap)

{

    WebPState *sp = LState(tif);

    switch (tag)

    {

        case TIFFTAG_WEBP_LEVEL:

            *va_arg(ap, int *) = sp->quality_level;

            break;

        case TIFFTAG_WEBP_LOSSLESS:

            *va_arg(ap, int *) = sp->lossless;

            break;

        case TIFFTAG_WEBP_LOSSLESS_EXACT:

            *va_arg(ap, int *) = sp->lossless_exact;

            break;

        default:

            return (*sp->vgetparent)(tif, tag, ap);

    }

    return 1;

}

static const TIFFField TWebPFields[] = {

    {TIFFTAG_WEBP_LEVEL, 0, 0, TIFF_ANY, 0, TIFF_SETGET_INT, FIELD_PSEUDO, TRUE,

     FALSE, "WEBP quality", NULL},

    {TIFFTAG_WEBP_LOSSLESS, 0, 0, TIFF_ANY, 0, TIFF_SETGET_INT, FIELD_PSEUDO,

     TRUE, FALSE, "WEBP lossless/lossy", NULL},

    {TIFFTAG_WEBP_LOSSLESS_EXACT, 0, 0, TIFF_ANY, 0, TIFF_SETGET_INT,

     FIELD_PSEUDO, TRUE, FALSE, "WEBP exact lossless", NULL},

};

static uint64_t TWebPGetMaxCompressionRatio(TIFF *tif)

{

    /* See README_for_libtiff_developpers.md for raw data used to estimate

     * the maximum compression rate. */

    /* lossy compression: */

    /* return (tif->tif_dir.td_samplesperpixel == 4) ? 2199 : 1685; */

    /* lossless compression: */

    return (tif->tif_dir.td_samplesperpixel == 4) ? 104194 : 78146;

}

int TIFFInitWebP(TIFF *tif, int scheme)

{

    static const char module[] = "TIFFInitWebP";

    WebPState *sp;

    (void)scheme;

    assert(scheme == COMPRESSION_WEBP);

    /*

     * Merge codec-specific tag information.

     */

    if (!_TIFFMergeFields(tif, TWebPFields, TIFFArrayCount(TWebPFields)))

    {

        TIFFErrorExtR(tif, module, "Merging WebP codec-specific tags failed");

        return 0;

    }

    /*

     * Allocate state block so tag methods have storage to record values.

     */

    tif->tif_data = (uint8_t *)_TIFFmallocExt(tif, sizeof(WebPState));

    if (tif->tif_data == NULL)

        goto bad;

    sp = LState(tif);

    /*

     * Override parent get/set field methods.

     */

    sp->vgetparent = tif->tif_tagmethods.vgetfield;

    tif->tif_tagmethods.vgetfield = TWebPVGetField; /* hook for codec tags */

    sp->vsetparent = tif->tif_tagmethods.vsetfield;

    tif->tif_tagmethods.vsetfield = TWebPVSetField; /* hook for codec tags */

    /* Default values for codec-specific fields */

    sp->quality_level = 75; /* default comp. level */

    sp->lossless = 0;       /* default to false */

    sp->lossless_exact = 1; /* exact lossless mode (if lossless enabled) */

    sp->state = 0;

    sp->nSamples = 0;

    sp->psDecoder = NULL;

    sp->last_y = 0;

    sp->buffer_offset = 0;

    sp->pBuffer = NULL;

    /*

     * Install codec methods.

     * Notes:

     * encoderow is not supported

     */

    tif->tif_fixuptags = TWebPFixupTags;

    tif->tif_setupdecode = TWebPSetupDecode;

    tif->tif_predecode = TWebPPreDecode;

    tif->tif_decoderow = TWebPDecode;

    tif->tif_decodestrip = TWebPDecode;

    tif->tif_decodetile = TWebPDecode;

    tif->tif_setupencode = TWebPSetupEncode;

    tif->tif_preencode = TWebPPreEncode;

    tif->tif_postencode = TWebPPostEncode;

    tif->tif_encoderow = TWebPEncode;

    tif->tif_encodestrip = TWebPEncode;

    tif->tif_encodetile = TWebPEncode;

    tif->tif_cleanup = TWebPCleanup;

    tif->tif_getmaxcompressionratio = TWebPGetMaxCompressionRatio;

    return 1;

bad:

    TIFFErrorExtR(tif, module, "No space for WebP state block");

    return 0;

}

#endif /* WEBP_SUPPORT */