Added seek support to make writing jp2 files work. Also added support for directly using an fd rather than relying on the Python loop, if we have a real fd.

This commit is contained in:
Alastair Houghton 2014-03-14 11:21:08 +00:00
parent 61fb89ec54
commit cb1f990a92
8 changed files with 306 additions and 73 deletions

View File

@ -156,9 +156,13 @@ class Jpeg2KImageFile(ImageFile.ImageFile):
self.reduce = 0
self.layers = 0
fd = -1
if hasattr(self.fp, "fileno"):
fd = self.fp.fileno()
self.tile = [('jpeg2k', (0, 0) + self.size, 0,
(self.codec, self.reduce, self.layers))]
(self.codec, self.reduce, self.layers, fd))]
def load(self):
if self.reduce:
@ -181,6 +185,38 @@ def _save(im, fp, filename):
kind = 'j2k'
else:
kind = 'jp2'
# Get the keyword arguments
info = im.encoderinfo
offset = info.get('offset', None)
tile_offset = info.get('tile_offset', None)
tile_size = info.get('tile_size', None)
quality_mode = info.get('quality_mode', 'rates')
quality_layers = info.get('quality_layers', None)
num_resolutions = info.get('num_resolutions', 0)
cblk_size = info.get('codeblock_size', None)
irreversible = info.get('irreversible', False)
progression = info.get('progression', 'LRCP')
cinema_mode = info.get('cinema_mode', 'no')
fd = -1
if hasattr(fp, "fileno"):
fd = fp.fileno()
im.encoderconfig = (
offset,
tile_offset,
tile_size,
quality_mode,
quality_layers,
num_resolutions,
cblk_size,
irreversible,
progression,
cinema_mode,
fd
)
ImageFile._save(im, fp, [('jpeg2k', (0, 0)+im.size, 0, kind)])

View File

@ -796,8 +796,9 @@ PyImaging_Jpeg2KDecoderNew(PyObject* self, PyObject* args)
OPJ_CODEC_FORMAT codec_format;
int reduce = 0;
int layers = 0;
if (!PyArg_ParseTuple(args, "ss|ii", &mode, &format,
&reduce, &layers))
int fd = -1;
if (!PyArg_ParseTuple(args, "ss|iii", &mode, &format,
&reduce, &layers, &fd))
return NULL;
if (strcmp(format, "j2k") == 0)
@ -819,6 +820,7 @@ PyImaging_Jpeg2KDecoderNew(PyObject* self, PyObject* args)
context = (JPEG2KDECODESTATE *)decoder->state.context;
context->fd = fd;
context->format = codec_format;
context->reduce = reduce;
context->layers = layers;

View File

@ -837,16 +837,18 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args)
PyObject *quality_layers = NULL;
int num_resolutions = 0;
PyObject *cblk_size = NULL;
int irreversible = 0;
PyObject *irreversible = NULL;
char *progression = "LRCP";
OPJ_PROG_ORDER prog_order;
char *cinema_mode = "no";
OPJ_CINEMA_MODE cine_mode;
int fd = -1;
if (!PyArg_ParseTuple(args, "ss|OOOsOiOpss", &mode, &format,
if (!PyArg_ParseTuple(args, "ss|OOOsOIOOssi", &mode, &format,
&offset, &tile_offset, &tile_size,
&quality_mode, &quality_layers, &num_resolutions,
&cblk_size, &irreversible, &progression, &cinema_mode))
&cblk_size, &irreversible, &progression, &cinema_mode,
&fd))
return NULL;
if (strcmp (format, "j2k") == 0)
@ -891,6 +893,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args)
context = (JPEG2KENCODESTATE *)encoder->state.context;
context->fd = fd;
context->format = codec_format;
context->offset_x = context->offset_y = 0;
@ -905,6 +908,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args)
if (quality_layers && PySequence_Check(quality_layers)) {
context->quality_is_in_db = strcmp (quality_mode, "dB") == 0;
context->quality_layers = quality_layers;
Py_INCREF(quality_layers);
}
context->num_resolutions = num_resolutions;
@ -913,7 +917,7 @@ PyImaging_Jpeg2KEncoderNew(PyObject *self, PyObject *args)
&context->cblk_width,
&context->cblk_height);
context->irreversible = irreversible;
context->irreversible = PyObject_IsTrue(irreversible);
context->progression = prog_order;
context->cinema_mode = cine_mode;

View File

@ -512,12 +512,23 @@ typedef int (*ImagingIncrementalCodecEntry)(Imaging im,
ImagingCodecState state,
ImagingIncrementalCodec codec);
extern ImagingIncrementalCodec ImagingIncrementalCodecCreate(ImagingIncrementalCodecEntry codec_entry, Imaging im, ImagingCodecState state);
enum {
INCREMENTAL_CODEC_READ = 1,
INCREMENTAL_CODEC_WRITE = 2
};
enum {
INCREMENTAL_CODEC_NOT_SEEKABLE = 0,
INCREMENTAL_CODEC_SEEKABLE = 1
};
extern ImagingIncrementalCodec ImagingIncrementalCodecCreate(ImagingIncrementalCodecEntry codec_entry, Imaging im, ImagingCodecState state, int read_or_write, int seekable, int fd);
extern void ImagingIncrementalCodecDestroy(ImagingIncrementalCodec codec);
extern int ImagingIncrementalCodecPushBuffer(ImagingIncrementalCodec codec, UINT8 *buf, int bytes);
extern size_t ImagingIncrementalCodecRead(ImagingIncrementalCodec codec, void *buffer, size_t bytes);
extern ssize_t ImagingIncrementalCodecRead(ImagingIncrementalCodec codec, void *buffer, size_t bytes);
extern off_t ImagingIncrementalCodecSkip(ImagingIncrementalCodec codec, off_t bytes);
extern size_t ImagingIncrementalCodecWrite(ImagingIncrementalCodec codec, const void *buffer, size_t bytes);
extern ssize_t ImagingIncrementalCodecWrite(ImagingIncrementalCodec codec, const void *buffer, size_t bytes);
extern off_t ImagingIncrementalCodecSeek(ImagingIncrementalCodec codec, off_t bytes);
extern size_t ImagingIncrementalCodecBytesInBuffer(ImagingIncrementalCodec codec);
/* Errcodes */

View File

@ -35,6 +35,11 @@
thinking that the image is truncated, whereas generally you want it to
pass the EOF condition (0 bytes to read) through to your code. */
/* Additional complication: *Some* codecs need to seek; this is fine if
there is a file descriptor, but if we're buffering data it becomes
awkward. The incremental adaptor now contains code to handle these
two cases. */
#ifdef _WIN32
#include <windows.h>
#include <process.h>
@ -64,18 +69,24 @@ struct ImagingIncrementalCodecStruct {
pthread_cond_t data_cond;
pthread_t thread;
#endif
ImagingIncrementalCodecEntry entry;
Imaging im;
ImagingCodecState state;
ImagingIncrementalCodecEntry entry;
Imaging im;
ImagingCodecState state;
struct {
UINT8 *buffer;
UINT8 *ptr;
UINT8 *end;
int fd;
UINT8 *buffer; /* Base of buffer */
UINT8 *ptr; /* Current pointer in buffer */
UINT8 *top; /* Highest point in buffer we've used */
UINT8 *end; /* End of buffer */
} stream;
int started;
int result;
int read_or_write;
int seekable;
int started;
int result;
};
static void flush_stream(ImagingIncrementalCodec codec);
#if _WIN32
static void __stdcall
codec_thread(void *ptr)
@ -84,6 +95,8 @@ codec_thread(void *ptr)
codec->result = codec->entry(codec->im, codec->state, codec);
flush_stream(codec);
SetEvent(codec->hCodecEvent);
}
#else
@ -94,18 +107,54 @@ codec_thread(void *ptr)
codec->result = codec->entry(codec->im, codec->state, codec);
flush_stream(codec);
pthread_mutex_lock(&codec->codec_mutex);
pthread_cond_signal(&codec->codec_cond);
pthread_mutex_unlock(&codec->codec_mutex);
return NULL;
}
#endif
static void
flush_stream(ImagingIncrementalCodec codec)
{
/* This is to flush data from the write buffer for a seekable write
codec. */
if (codec->read_or_write != INCREMENTAL_CODEC_WRITE
|| codec->state->errcode != IMAGING_CODEC_END
|| !codec->seekable
|| codec->stream.fd >= 0)
return;
DEBUG("flushing data\n");
UINT8 *buffer = codec->stream.buffer;
size_t bytes = codec->stream.ptr - codec->stream.buffer;
codec->state->errcode = 0;
codec->seekable = INCREMENTAL_CODEC_NOT_SEEKABLE;
codec->stream.buffer = codec->stream.ptr = codec->stream.end
= codec->stream.top = NULL;
ImagingIncrementalCodecWrite(codec, buffer, bytes);
codec->state->errcode = IMAGING_CODEC_END;
codec->result = (int)ImagingIncrementalCodecBytesInBuffer(codec);
free(buffer);
}
/**
* Create a new incremental codec */
ImagingIncrementalCodec
ImagingIncrementalCodecCreate(ImagingIncrementalCodecEntry codec_entry,
Imaging im,
ImagingCodecState state)
ImagingCodecState state,
int read_or_write,
int seekable,
int fd)
{
ImagingIncrementalCodec codec = (ImagingIncrementalCodec)malloc(sizeof(struct ImagingIncrementalCodecStruct));
@ -113,8 +162,15 @@ ImagingIncrementalCodecCreate(ImagingIncrementalCodecEntry codec_entry,
codec->im = im;
codec->state = state;
codec->result = 0;
codec->stream.buffer = codec->stream.ptr = codec->stream.end = NULL;
codec->stream.fd = fd;
codec->stream.buffer = codec->stream.ptr = codec->stream.end
= codec->stream.top = NULL;
codec->started = 0;
codec->seekable = seekable;
codec->read_or_write = read_or_write;
if (fd >= 0)
lseek(fd, 0, SEEK_SET);
/* System specific set-up */
#if _WIN32
@ -223,7 +279,11 @@ ImagingIncrementalCodecDestroy(ImagingIncrementalCodec codec)
pthread_mutex_lock(&codec->data_mutex);
#endif
codec->stream.buffer = codec->stream.ptr = codec->stream.end = NULL;
if (codec->seekable && codec->stream.fd < 0)
free (codec->stream.buffer);
codec->stream.buffer = codec->stream.ptr = codec->stream.end
= codec->stream.top = NULL;
#ifdef _WIN32
SetEvent(codec->hDataEvent);
@ -264,6 +324,22 @@ ImagingIncrementalCodecPushBuffer(ImagingIncrementalCodec codec,
pthread_cond_signal(&codec->start_cond);
#endif
codec->started = 1;
/* Wait for the thread to ask for data */
#ifdef _WIN32
WaitForSingleObject(codec->hCodecEvent);
#else
pthread_mutex_lock(&codec->codec_mutex);
pthread_cond_wait(&codec->codec_cond, &codec->codec_mutex);
pthread_mutex_unlock(&codec->codec_mutex);
#endif
}
/* Codecs using an fd don't need data, so when we get here, we're done */
if (codec->stream.fd >= 0) {
DEBUG("got result %d\n", codec->result);
return codec->result;
}
DEBUG("providing %p, %d\n", buf, bytes);
@ -272,8 +348,30 @@ ImagingIncrementalCodecPushBuffer(ImagingIncrementalCodec codec,
pthread_mutex_lock(&codec->data_mutex);
#endif
codec->stream.buffer = codec->stream.ptr = buf;
codec->stream.end = buf + bytes;
if (codec->read_or_write == INCREMENTAL_CODEC_READ
&& codec->seekable && codec->stream.fd < 0) {
/* In this specific case, we append to a buffer we allocate ourselves */
size_t old_size = codec->stream.end - codec->stream.buffer;
size_t new_size = codec->stream.end - codec->stream.buffer + bytes;
UINT8 *new = (UINT8 *)realloc (codec->stream.buffer, new_size);
if (!new) {
codec->state->errcode = IMAGING_CODEC_MEMORY;
#ifndef _WIN32
pthread_mutex_unlock(&codec->data_mutex);
#endif
return -1;
}
codec->stream.ptr = codec->stream.ptr - codec->stream.buffer + new;
codec->stream.end = new + new_size;
codec->stream.buffer = new;
memcpy(new + old_size, buf, bytes);
} else {
codec->stream.buffer = codec->stream.ptr = buf;
codec->stream.end = buf + bytes;
}
#ifdef _WIN32
SetEvent(codec->hDataEvent);
@ -298,15 +396,27 @@ ImagingIncrementalCodecBytesInBuffer(ImagingIncrementalCodec codec)
return codec->stream.ptr - codec->stream.buffer;
}
size_t
ssize_t
ImagingIncrementalCodecRead(ImagingIncrementalCodec codec,
void *buffer, size_t bytes)
{
UINT8 *ptr = (UINT8 *)buffer;
size_t done = 0;
if (codec->read_or_write == INCREMENTAL_CODEC_WRITE) {
DEBUG("attempt to read from write codec\n");
return -1;
}
DEBUG("reading (want %llu bytes)\n", (unsigned long long)bytes);
if (codec->stream.fd >= 0) {
off_t offset = lseek(codec->stream.fd, 0, SEEK_CUR);
ssize_t ret = read(codec->stream.fd, buffer, bytes);
DEBUG("read %lld bytes from fd at %lld\n", (long long)ret, (long long)offset);
return ret;
}
#ifndef _WIN32
pthread_mutex_lock(&codec->data_mutex);
#endif
@ -331,9 +441,11 @@ ImagingIncrementalCodecRead(ImagingIncrementalCodec codec,
#endif
remaining = codec->stream.end - codec->stream.ptr;
codec->stream.top = codec->stream.end;
DEBUG("got %llu bytes\n", (unsigned long long)remaining);
}
if (todo > remaining)
todo = remaining;
@ -357,12 +469,30 @@ ImagingIncrementalCodecRead(ImagingIncrementalCodec codec,
off_t
ImagingIncrementalCodecSkip(ImagingIncrementalCodec codec,
off_t bytes)
off_t bytes)
{
off_t done = 0;
DEBUG("skipping (want %llu bytes)\n", (unsigned long long)bytes);
/* In write mode, explicitly fill with zeroes */
if (codec->read_or_write == INCREMENTAL_CODEC_WRITE) {
static const UINT8 zeroes[256] = { 0 };
off_t done = 0;
while (bytes) {
size_t todo = bytes > 256 ? 256 : bytes;
ssize_t written = ImagingIncrementalCodecWrite(codec, zeroes, todo);
if (written <= 0)
break;
done += written;
bytes -= written;
}
return done;
}
if (codec->stream.fd >= 0)
return lseek(codec->stream.fd, bytes, SEEK_CUR);
#ifndef _WIN32
pthread_mutex_lock(&codec->data_mutex);
#endif
@ -388,6 +518,7 @@ ImagingIncrementalCodecSkip(ImagingIncrementalCodec codec,
remaining = codec->stream.end - codec->stream.ptr;
}
if (todo > remaining)
todo = remaining;
@ -407,15 +538,23 @@ ImagingIncrementalCodecSkip(ImagingIncrementalCodec codec,
return done;
}
size_t
ssize_t
ImagingIncrementalCodecWrite(ImagingIncrementalCodec codec,
const void *buffer, size_t bytes)
{
const UINT8 *ptr = (const UINT8 *)buffer;
size_t done = 0;
if (codec->read_or_write == INCREMENTAL_CODEC_READ) {
DEBUG("attempt to write from read codec\n");
return -1;
}
DEBUG("write (have %llu bytes)\n", (unsigned long long)bytes);
if (codec->stream.fd >= 0)
return write(codec->stream.fd, buffer, bytes);
#ifndef _WIN32
pthread_mutex_lock(&codec->data_mutex);
#endif
@ -424,20 +563,40 @@ ImagingIncrementalCodecWrite(ImagingIncrementalCodec codec,
size_t remaining = codec->stream.end - codec->stream.ptr;
if (!remaining) {
DEBUG("waiting for space\n");
if (codec->seekable && codec->stream.fd < 0) {
/* In this case, we maintain the stream buffer ourselves */
size_t old_size = codec->stream.top - codec->stream.buffer;
size_t new_size = (old_size + bytes + 65535) & ~65535;
UINT8 *new = (UINT8 *)realloc(codec->stream.buffer, new_size);
if (!new) {
codec->state->errcode = IMAGING_CODEC_MEMORY;
#ifndef _WIN32
pthread_mutex_unlock(&codec->data_mutex);
#endif
return done == 0 ? -1 : done;
}
codec->stream.ptr = codec->stream.ptr - codec->stream.buffer + new;
codec->stream.buffer = new;
codec->stream.end = new + new_size;
codec->stream.top = new + old_size;
} else {
DEBUG("waiting for space\n");
#ifndef _WIN32
pthread_mutex_lock(&codec->codec_mutex);
pthread_mutex_lock(&codec->codec_mutex);
#endif
codec->result = (int)(codec->stream.ptr - codec->stream.buffer);
codec->result = (int)(codec->stream.ptr - codec->stream.buffer);
#if _WIN32
SetEvent(codec->hCodecEvent);
WaitForSingleObject(codec->hDataEvent);
SetEvent(codec->hCodecEvent);
WaitForSingleObject(codec->hDataEvent);
#else
pthread_cond_signal(&codec->codec_cond);
pthread_mutex_unlock(&codec->codec_mutex);
pthread_cond_wait(&codec->data_cond, &codec->data_mutex);
pthread_cond_signal(&codec->codec_cond);
pthread_mutex_unlock(&codec->codec_mutex);
pthread_cond_wait(&codec->data_cond, &codec->data_mutex);
#endif
}
remaining = codec->stream.end - codec->stream.ptr;
@ -455,6 +614,10 @@ ImagingIncrementalCodecWrite(ImagingIncrementalCodec codec,
done += todo;
ptr += todo;
}
if (codec->stream.ptr > codec->stream.top)
codec->stream.top = codec->stream.ptr;
#ifndef _WIN32
pthread_mutex_unlock(&codec->data_mutex);
#endif
@ -463,3 +626,33 @@ ImagingIncrementalCodecWrite(ImagingIncrementalCodec codec,
return done;
}
off_t
ImagingIncrementalCodecSeek(ImagingIncrementalCodec codec,
off_t bytes)
{
DEBUG("seeking (going to %llu bytes)\n", (unsigned long long)bytes);
if (codec->stream.fd >= 0)
return lseek(codec->stream.fd, bytes, SEEK_SET);
if (!codec->seekable) {
DEBUG("attempt to seek non-seekable stream\n");
return -1;
}
if (bytes < 0) {
DEBUG("attempt to seek before stream start\n");
return -1;
}
off_t buffered = codec->stream.top - codec->stream.buffer;
if (bytes <= buffered) {
DEBUG("seek within buffer\n");
codec->stream.ptr = codec->stream.buffer + bytes;
return bytes;
}
return buffered + ImagingIncrementalCodecSkip(codec, bytes - buffered);
}

View File

@ -17,6 +17,9 @@
typedef struct {
/* CONFIGURATION */
/* File descriptor, if available; otherwise, -1 */
int fd;
/* Specify the desired format */
OPJ_CODEC_FORMAT format;
@ -39,6 +42,9 @@ typedef struct {
typedef struct {
/* CONFIGURATION */
/* File descriptor, if available; otherwise, -1 */
int fd;
/* Specify the desired format */
OPJ_CODEC_FORMAT format;

View File

@ -53,15 +53,6 @@ j2k_read(void *p_buffer, OPJ_SIZE_T p_nb_bytes, void *p_user_data)
return len ? len : (OPJ_SIZE_T)-1;
}
static OPJ_SIZE_T
j2k_write(void *p_buffer, OPJ_SIZE_T p_nb_bytes, void *p_user_data)
{
/* This should never happen */
fprintf(stderr, "OpenJPEG has written to our read stream(!)");
abort();
return (OPJ_SIZE_T)-1;
}
static OPJ_OFF_T
j2k_skip(OPJ_OFF_T p_nb_bytes, void *p_user_data)
{
@ -71,15 +62,6 @@ j2k_skip(OPJ_OFF_T p_nb_bytes, void *p_user_data)
return pos ? pos : (OPJ_OFF_T)-1;
}
static OPJ_BOOL
j2k_seek(OPJ_OFF_T p_nb_bytes, void *p_user_data)
{
/* This should never happen */
fprintf(stderr, "OpenJPEG tried to seek our read stream(!)");
abort();
return OPJ_FALSE;
}
/* -------------------------------------------------------------------- */
/* Unpackers */
/* -------------------------------------------------------------------- */
@ -476,9 +458,7 @@ j2k_decode_entry(Imaging im, ImagingCodecState state,
}
opj_stream_set_read_function(stream, j2k_read);
opj_stream_set_write_function(stream, j2k_write);
opj_stream_set_skip_function(stream, j2k_skip);
opj_stream_set_seek_function(stream, j2k_seek);
opj_stream_set_user_data(stream, context->decoder);
@ -623,6 +603,7 @@ j2k_decode_entry(Imaging im, ImagingCodecState state,
}
state->state = J2K_STATE_DONE;
state->errcode = IMAGING_CODEC_END;
quick_exit:
if (codec)
@ -645,7 +626,10 @@ ImagingJpeg2KDecode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
if (state->state == J2K_STATE_START) {
context->decoder = ImagingIncrementalCodecCreate(j2k_decode_entry,
im, state);
im, state,
INCREMENTAL_CODEC_READ,
INCREMENTAL_CODEC_NOT_SEEKABLE,
context->fd);
if (!context->decoder) {
state->errcode = IMAGING_CODEC_BROKEN;

View File

@ -40,15 +40,6 @@ j2k_error(const char *msg, void *client_data)
/* Buffer output stream */
/* -------------------------------------------------------------------- */
static OPJ_SIZE_T
j2k_read(void *p_buffer, OPJ_SIZE_T p_nb_bytes, void *p_user_data)
{
/* This should never happen */
fprintf (stderr, "OpenJPEG has read from our write stream(!)");
abort();
return (OPJ_SIZE_T)-1;
}
static OPJ_SIZE_T
j2k_write(void *p_buffer, OPJ_SIZE_T p_nb_bytes, void *p_user_data)
{
@ -61,8 +52,8 @@ j2k_write(void *p_buffer, OPJ_SIZE_T p_nb_bytes, void *p_user_data)
static OPJ_OFF_T
j2k_skip(OPJ_OFF_T p_nb_bytes, void *p_user_data)
{
ImagingIncrementalCodec decoder = (ImagingIncrementalCodec)p_user_data;
off_t pos = ImagingIncrementalCodecSkip(decoder, p_nb_bytes);
ImagingIncrementalCodec encoder = (ImagingIncrementalCodec)p_user_data;
off_t pos = ImagingIncrementalCodecSkip(encoder, p_nb_bytes);
return pos ? pos : (OPJ_OFF_T)-1;
}
@ -70,10 +61,10 @@ j2k_skip(OPJ_OFF_T p_nb_bytes, void *p_user_data)
static OPJ_BOOL
j2k_seek(OPJ_OFF_T p_nb_bytes, void *p_user_data)
{
/* This should never happen */
fprintf(stderr, "OpenJPEG tried to seek our write stream(!)");
abort();
return OPJ_FALSE;
ImagingIncrementalCodec encoder = (ImagingIncrementalCodec)p_user_data;
off_t pos = ImagingIncrementalCodecSeek(encoder, p_nb_bytes);
return pos == p_nb_bytes;
}
/* -------------------------------------------------------------------- */
@ -259,7 +250,6 @@ j2k_encode_entry(Imaging im, ImagingCodecState state,
goto quick_exit;
}
opj_stream_set_read_function(stream, j2k_read);
opj_stream_set_write_function(stream, j2k_write);
opj_stream_set_skip_function(stream, j2k_skip);
opj_stream_set_seek_function(stream, j2k_seek);
@ -499,12 +489,19 @@ ImagingJpeg2KEncode(Imaging im, ImagingCodecState state, UINT8 *buf, int bytes)
{
JPEG2KENCODESTATE *context = (JPEG2KENCODESTATE *)state->context;
if (state->state == J2K_STATE_DONE || state->state == J2K_STATE_FAILED)
if (state->state == J2K_STATE_FAILED)
return -1;
if (state->state == J2K_STATE_START) {
int seekable = (context->format != OPJ_CODEC_J2K
? INCREMENTAL_CODEC_SEEKABLE
: INCREMENTAL_CODEC_NOT_SEEKABLE);
context->encoder = ImagingIncrementalCodecCreate(j2k_encode_entry,
im, state);
im, state,
INCREMENTAL_CODEC_WRITE,
seekable,
context->fd);
if (!context->encoder) {
state->errcode = IMAGING_CODEC_BROKEN;