From 1d531d5b24320126d6167dfc5830490e460431a7 Mon Sep 17 00:00:00 2001 From: Julien Moutte Date: Tue, 18 Oct 2005 22:44:11 +0000 Subject: ext/libpng/gstpngdec.*: Complete rewrite of pngdec. It's now very nice and handle push/pull based model. if you have ... Original commit message from CVS: 2005-10-19 Julien MOUTTE * ext/libpng/gstpngdec.c: (gst_pngdec_class_init), (gst_pngdec_init), (user_error_fn), (user_warning_fn), (user_info_callback), (user_endrow_callback), (user_end_callback), (user_read_data), (gst_pngdec_caps_create_and_set), (gst_pngdec_task), (gst_pngdec_chain), (gst_pngdec_sink_event), (gst_pngdec_libpng_clear), (gst_pngdec_libpng_init), (gst_pngdec_change_state), (gst_pngdec_sink_activate_push), (gst_pngdec_sink_activate_pull), (gst_pngdec_sink_activate): * ext/libpng/gstpngdec.h: Complete rewrite of pngdec. It's now very nice and handle push/pull based model. if you have filesrc connected to it, it will do random access to load the png file. If you have a network source that can't do _getrange, it does progressive loading through the chain function. * gst/alpha/gstalphacolor.c: (gst_alpha_color_transform_caps), (transform_rgb), (transform_bgr): Fix caps negotiation correctly thanks to Master Wim Taymans ;-) --- ext/libpng/gstpngdec.c | 597 +++++++++++++++++++++++++++++++++++++------------ ext/libpng/gstpngdec.h | 8 +- 2 files changed, 465 insertions(+), 140 deletions(-) (limited to 'ext/libpng') diff --git a/ext/libpng/gstpngdec.c b/ext/libpng/gstpngdec.c index c28ca86a..3d9c7cca 100644 --- a/ext/libpng/gstpngdec.c +++ b/ext/libpng/gstpngdec.c @@ -36,21 +36,25 @@ static void gst_pngdec_base_init (gpointer g_class); static void gst_pngdec_class_init (GstPngDecClass * klass); static void gst_pngdec_init (GstPngDec * pngdec); -static GstFlowReturn gst_pngdec_chain (GstPad * pad, GstBuffer * buf); +static gboolean gst_pngdec_libpng_init (GstPngDec * pngdec); +static gboolean gst_pngdec_libpng_clear (GstPngDec * pngdec); -static GstElementClass *parent_class = NULL; +static GstStateChangeReturn gst_pngdec_change_state (GstElement * element, + GstStateChange transition); -static void -user_error_fn (png_structp png_ptr, png_const_charp error_msg) -{ - g_warning ("%s", error_msg); -} +static gboolean gst_pngdec_sink_activate_push (GstPad * sinkpad, + gboolean active); +static gboolean gst_pngdec_sink_activate_pull (GstPad * sinkpad, + gboolean active); +static gboolean gst_pngdec_sink_activate (GstPad * sinkpad); -static void -user_warning_fn (png_structp png_ptr, png_const_charp warning_msg) -{ - g_warning ("%s", warning_msg); -} +static GstFlowReturn gst_pngdec_caps_create_and_set (GstPngDec * pngdec); + +static void gst_pngdec_task (GstPad * pad); +static GstFlowReturn gst_pngdec_chain (GstPad * pad, GstBuffer * buffer); +static gboolean gst_pngdec_sink_event (GstPad * pad, GstEvent * event); + +static GstElementClass *parent_class = NULL; GType gst_pngdec_get_type (void) @@ -113,6 +117,8 @@ gst_pngdec_class_init (GstPngDecClass * klass) parent_class = g_type_class_ref (GST_TYPE_ELEMENT); + gstelement_class->change_state = gst_pngdec_change_state; + GST_DEBUG_CATEGORY_INIT (pngdec_debug, "pngdec", 0, "PNG image decoder"); } @@ -122,6 +128,13 @@ gst_pngdec_init (GstPngDec * pngdec) { pngdec->sinkpad = gst_pad_new_from_template (gst_static_pad_template_get (&gst_pngdec_sink_pad_template), "sink"); + gst_pad_set_activate_function (pngdec->sinkpad, gst_pngdec_sink_activate); + gst_pad_set_activatepush_function (pngdec->sinkpad, + gst_pngdec_sink_activate_push); + gst_pad_set_activatepull_function (pngdec->sinkpad, + gst_pngdec_sink_activate_pull); + gst_pad_set_chain_function (pngdec->sinkpad, gst_pngdec_chain); + gst_pad_set_event_function (pngdec->sinkpad, gst_pngdec_sink_event); gst_pad_use_fixed_caps (pngdec->sinkpad); gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->sinkpad); @@ -130,205 +143,511 @@ gst_pngdec_init (GstPngDec * pngdec) gst_pad_use_fixed_caps (pngdec->srcpad); gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->srcpad); - gst_pad_set_chain_function (pngdec->sinkpad, gst_pngdec_chain); + /* gst_pad_set_chain_function (pngdec->sinkpad, gst_pngdec_chain); */ + pngdec->buffer_out = NULL; pngdec->png = NULL; pngdec->info = NULL; + pngdec->endinfo = NULL; + pngdec->setup = FALSE; pngdec->color_type = -1; pngdec->width = -1; pngdec->height = -1; + pngdec->bpp = -1; pngdec->fps = 0.0; } static void -user_read_data (png_structp png_ptr, png_bytep data, png_size_t length) +user_error_fn (png_structp png_ptr, png_const_charp error_msg) { - GstPngDec *dec; + GST_ERROR ("%s", error_msg); +} + +static void +user_warning_fn (png_structp png_ptr, png_const_charp warning_msg) +{ + GST_WARNING ("%s", warning_msg); +} + +static void +user_info_callback (png_structp png_ptr, png_infop info) +{ + GstPngDec *pngdec = NULL; + GstFlowReturn ret = GST_FLOW_OK; + gint bpc = 0; + png_uint_32 width, height; + size_t buffer_size; + GstBuffer *buffer = NULL; + + pngdec = GST_PNGDEC (png_ptr->io_ptr); - dec = GST_PNGDEC (png_ptr->io_ptr); + GST_LOG ("info ready"); - GST_LOG ("reading %d bytes of data at offset %d", length, dec->offset); + /* Get bits per channel */ + bpc = png_get_bit_depth (pngdec->png, pngdec->info); - if (GST_BUFFER_SIZE (dec->buffer_in) < dec->offset + length) { - g_warning ("reading past end of buffer"); + /* We don't handle 16 bits per color, strip down to 8 */ + if (bpc == 16) { + GST_LOG ("this is a 16 bits per channel PNG image, strip down to 8 bits"); + png_set_strip_16 (pngdec->png); } - memcpy (data, GST_BUFFER_DATA (dec->buffer_in) + dec->offset, length); + /* Update the info structure */ + png_read_update_info (pngdec->png, pngdec->info); + + /* Get IHDR header again after transformation settings */ + + png_get_IHDR (pngdec->png, pngdec->info, &width, &height, + &bpc, &pngdec->color_type, NULL, NULL, NULL); + + pngdec->width = width; + pngdec->height = height; + + /* Generate the caps and configure */ + ret = gst_pngdec_caps_create_and_set (pngdec); + if (ret != GST_FLOW_OK) { + goto beach; + } - dec->offset += length; + /* Allocate output buffer */ + pngdec->rowbytes = png_get_rowbytes (pngdec->png, pngdec->info); + buffer_size = pngdec->height * GST_ROUND_UP_4 (pngdec->rowbytes); + ret = gst_pad_alloc_buffer (pngdec->srcpad, GST_BUFFER_OFFSET_NONE, + buffer_size, GST_PAD_CAPS (pngdec->srcpad), &buffer); + if (ret != GST_FLOW_OK) { + goto beach; + } + + pngdec->buffer_out = buffer; + +beach: + pngdec->ret = ret; } -#define ROUND_UP_4(x) (((x) + 3) & ~3) +static void +user_endrow_callback (png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) +{ + GstPngDec *pngdec = NULL; + + pngdec = GST_PNGDEC (png_ptr->io_ptr); + + /* FIXME: implement interlaced pictures */ + + if (GST_IS_BUFFER (pngdec->buffer_out)) { + size_t offset = row_num * GST_ROUND_UP_4 (pngdec->rowbytes); + + GST_LOG ("got row %d, copying in buffer %p at offset %d", row_num, + pngdec->buffer_out, offset); + memcpy (GST_BUFFER_DATA (pngdec->buffer_out) + offset, new_row, + pngdec->rowbytes); + pngdec->ret = GST_FLOW_OK; + } else { + GST_LOG ("we don't have any output buffer to write this row !"); + pngdec->ret = GST_FLOW_ERROR; + } +} + +static void +user_end_callback (png_structp png_ptr, png_infop info) +{ + GstPngDec *pngdec = NULL; + + pngdec = GST_PNGDEC (png_ptr->io_ptr); + + GST_LOG ("and we are done reading this image, pushing it and setting eos"); + + /* Push our buffer and then EOS */ + pngdec->ret = gst_pad_push (pngdec->srcpad, pngdec->buffer_out); + pngdec->ret = gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ()); +} + +static void +user_read_data (png_structp png_ptr, png_bytep data, png_size_t length) +{ + GstPngDec *pngdec; + GstBuffer *buffer; + GstFlowReturn ret = GST_FLOW_OK; + + pngdec = GST_PNGDEC (png_ptr->io_ptr); + + GST_LOG ("reading %d bytes of data at offset %d", length, pngdec->offset); + + ret = gst_pad_pull_range (pngdec->sinkpad, pngdec->offset, length, &buffer); + if ((ret != GST_FLOW_OK) || (GST_BUFFER_SIZE (buffer) != length)) + goto pause; + + memcpy (data, GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer)); + + pngdec->offset += length; + + return; + +pause: + GST_LOG_OBJECT (pngdec, "pausing task, reason %s", gst_flow_get_name (ret)); + gst_pad_pause_task (pngdec->sinkpad); + if (GST_FLOW_IS_FATAL (ret)) { + gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ()); + GST_ELEMENT_ERROR (pngdec, STREAM, STOPPED, + (NULL), ("stream stopped, reason %s", gst_flow_get_name (ret))); + } +} static GstFlowReturn -gst_pngdec_chain (GstPad * pad, GstBuffer * buf) +gst_pngdec_caps_create_and_set (GstPngDec * pngdec) { GstFlowReturn ret = GST_FLOW_OK; + GstCaps *caps = NULL, *res = NULL; + GstPadTemplate *templ = NULL; + + g_return_val_if_fail (GST_IS_PNGDEC (pngdec), GST_FLOW_ERROR); + + GST_LOG ("this is a %dx%d PNG image", pngdec->width, pngdec->height); + + switch (pngdec->color_type) { + case PNG_COLOR_TYPE_RGB: + GST_LOG ("we have no alpha channel, depth is 24 bits"); + pngdec->bpp = 24; + break; + case PNG_COLOR_TYPE_RGB_ALPHA: + GST_LOG ("we have an alpha channel, depth is 32 bits"); + pngdec->bpp = 32; + break; + default: + GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL), + ("pngdec does not support grayscale or paletted data yet")); + ret = GST_FLOW_ERROR; + goto beach; + } + + caps = gst_caps_new_simple ("video/x-raw-rgb", + "width", G_TYPE_INT, pngdec->width, + "height", G_TYPE_INT, pngdec->height, + "bpp", G_TYPE_INT, pngdec->bpp, + "framerate", G_TYPE_DOUBLE, pngdec->fps, NULL); + + templ = gst_static_pad_template_get (&gst_pngdec_src_pad_template); + + res = gst_caps_intersect (caps, gst_pad_template_get_caps (templ)); + + gst_caps_unref (caps); + + if (!gst_pad_set_caps (pngdec->srcpad, res)) { + ret = GST_FLOW_ERROR; + } + + GST_LOG ("our caps %s", gst_caps_to_string (res)); + + gst_caps_unref (res); + +beach: + return ret; +} + +static void +gst_pngdec_task (GstPad * pad) +{ GstPngDec *pngdec; - png_uint_32 width, height; - gint depth, color; + GstBuffer *buffer = NULL; + size_t buffer_size = 0; + gint i = 0, bpc = 0; png_bytep *rows, inp; - GstBuffer *out; - gint i; + png_uint_32 width, height, rowbytes; + GstFlowReturn ret = GST_FLOW_OK; + + pngdec = GST_PNGDEC (GST_OBJECT_PARENT (pad)); + + /* Let libpng come back here on error */ + if (setjmp (png_jmpbuf (pngdec->png))) { + ret = GST_FLOW_ERROR; + goto pause; + } + + /* Set reading callback */ + png_set_read_fn (pngdec->png, pngdec, user_read_data); + + /* Read info */ + png_read_info (pngdec->png, pngdec->info); + + /* Get bits per channel */ + bpc = png_get_bit_depth (pngdec->png, pngdec->info); + + /* We don't handle 16 bits per color, strip down to 8 */ + if (bpc == 16) { + GST_LOG ("this is a 16 bits per channel PNG image, strip down to 8 bits"); + png_set_strip_16 (pngdec->png); + } + + /* Update the info structure */ + png_read_update_info (pngdec->png, pngdec->info); + + /* Get IHDR header again after transformation settings */ + + png_get_IHDR (pngdec->png, pngdec->info, &width, &height, + &bpc, &pngdec->color_type, NULL, NULL, NULL); - GST_LOG ("chain"); + pngdec->width = width; + pngdec->height = height; - pngdec = GST_PNGDEC (gst_pad_get_parent (pad)); + /* Generate the caps and configure */ + ret = gst_pngdec_caps_create_and_set (pngdec); + if (ret != GST_FLOW_OK) { + goto pause; + } + + /* Allocate output buffer */ + rowbytes = png_get_rowbytes (pngdec->png, pngdec->info); + buffer_size = pngdec->height * GST_ROUND_UP_4 (rowbytes); + ret = gst_pad_alloc_buffer (pngdec->srcpad, GST_BUFFER_OFFSET_NONE, + buffer_size, GST_PAD_CAPS (pngdec->srcpad), &buffer); + if (ret != GST_FLOW_OK) { + goto pause; + } + + rows = (png_bytep *) g_malloc (sizeof (png_bytep) * height); + + inp = GST_BUFFER_DATA (buffer); + + for (i = 0; i < height; i++) { + rows[i] = inp; + inp += GST_ROUND_UP_4 (rowbytes); + } + + /* Read the actual picture */ + png_read_image (pngdec->png, rows); + free (rows); + + /* Push the raw RGB frame */ + ret = gst_pad_push (pngdec->srcpad, buffer); + if (ret != GST_FLOW_OK) { + goto pause; + } + + /* And we are done */ + gst_pad_pause_task (pngdec->sinkpad); + gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ()); + return; + +pause: + GST_LOG_OBJECT (pngdec, "pausing task, reason %s", gst_flow_get_name (ret)); + gst_pad_pause_task (pngdec->sinkpad); + if (GST_FLOW_IS_FATAL (ret)) { + gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ()); + GST_ELEMENT_ERROR (pngdec, STREAM, STOPPED, + (NULL), ("stream stopped, reason %s", gst_flow_get_name (ret))); + } +} + +static GstFlowReturn +gst_pngdec_chain (GstPad * pad, GstBuffer * buffer) +{ + GstPngDec *pngdec; + GstFlowReturn ret = GST_FLOW_OK; - if (!GST_PAD_IS_USABLE (pngdec->srcpad)) { - gst_buffer_unref (buf); - ret = GST_FLOW_UNEXPECTED; + pngdec = GST_PNGDEC (GST_OBJECT_PARENT (pad)); + + if (!pngdec->setup) { + GST_LOG ("we are not configured yet"); + ret = GST_FLOW_WRONG_STATE; + goto beach; + } + + /* Something is going wrong in our callbacks */ + if (pngdec->ret != GST_FLOW_OK) { + ret = pngdec->ret; + goto beach; + } + + /* Let libpng come back here on error */ + if (setjmp (png_jmpbuf (pngdec->png))) { + ret = GST_FLOW_ERROR; goto beach; } - pngdec->buffer_in = buf; + /* Progressive loading of the PNG image */ + png_process_data (pngdec->png, pngdec->info, GST_BUFFER_DATA (buffer), + GST_BUFFER_SIZE (buffer)); + + /* And release the buffer */ + gst_buffer_unref (buffer); + +beach: + return ret; +} + +static gboolean +gst_pngdec_sink_event (GstPad * pad, GstEvent * event) +{ + GstPngDec *pngdec; + + pngdec = GST_PNGDEC (GST_OBJECT_PARENT (pad)); + + switch (GST_EVENT_TYPE (event)) { + case GST_EVENT_EOS: + gst_pngdec_libpng_clear (pngdec); + default: + return gst_pad_event_default (pad, event); + } +} + + +/* Clean up the libpng structures */ +static gboolean +gst_pngdec_libpng_clear (GstPngDec * pngdec) +{ + png_infopp info = NULL, endinfo = NULL; + + g_return_val_if_fail (GST_IS_PNGDEC (pngdec), FALSE); + + GST_LOG ("cleaning up libpng structures"); + + if (pngdec->info) { + info = &pngdec->info; + } + + if (pngdec->endinfo) { + endinfo = &pngdec->endinfo; + } + + if (pngdec->png) { + png_destroy_read_struct (&(pngdec->png), info, endinfo); + pngdec->png = NULL; + pngdec->info = NULL; + pngdec->endinfo = NULL; + } + + pngdec->bpp = pngdec->color_type = pngdec->height = pngdec->width = -1; pngdec->offset = 0; + pngdec->rowbytes = 0; + pngdec->buffer_out = NULL; + + pngdec->setup = FALSE; + + return TRUE; +} + +static gboolean +gst_pngdec_libpng_init (GstPngDec * pngdec) +{ + g_return_val_if_fail (GST_IS_PNGDEC (pngdec), FALSE); + + if (pngdec->setup) { + goto beach; + } /* initialize png struct stuff */ pngdec->png = png_create_read_struct (PNG_LIBPNG_VER_STRING, (png_voidp) NULL, user_error_fn, user_warning_fn); if (pngdec->png == NULL) { - gst_buffer_unref (buf); GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL), ("Failed to initialize png structure")); - ret = GST_FLOW_UNEXPECTED; goto beach; } pngdec->info = png_create_info_struct (pngdec->png); if (pngdec->info == NULL) { - gst_buffer_unref (buf); - png_destroy_read_struct (&(pngdec->png), (png_infopp) NULL, - (png_infopp) NULL); + gst_pngdec_libpng_clear (pngdec); GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL), ("Failed to initialize info structure")); - ret = GST_FLOW_UNEXPECTED; goto beach; } pngdec->endinfo = png_create_info_struct (pngdec->png); if (pngdec->endinfo == NULL) { - gst_buffer_unref (buf); - png_destroy_read_struct (&pngdec->png, &pngdec->info, (png_infopp) NULL); + gst_pngdec_libpng_clear (pngdec); GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL), ("Failed to initialize endinfo structure")); - ret = GST_FLOW_UNEXPECTED; goto beach; } - /* non-0 return is from a longjmp inside of libpng */ - if (setjmp (pngdec->png->jmpbuf) != 0) { - gst_buffer_unref (buf); - png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo); - GST_ELEMENT_ERROR (pngdec, LIBRARY, FAILED, (NULL), - ("returning from longjmp")); - ret = GST_FLOW_UNEXPECTED; - goto beach; - } + pngdec->setup = TRUE; - png_set_read_fn (pngdec->png, pngdec, user_read_data); +beach: + return pngdec->setup; +} - png_read_info (pngdec->png, pngdec->info); - png_get_IHDR (pngdec->png, pngdec->info, &width, &height, - &depth, &color, NULL, NULL, NULL); - - if (pngdec->info->bit_depth != 8) { - gst_buffer_unref (buf); - png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo); - GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL), - ("pngdec only supports 8 bit images for now")); - ret = GST_FLOW_UNEXPECTED; - goto beach; +static GstStateChangeReturn +gst_pngdec_change_state (GstElement * element, GstStateChange transition) +{ + GstStateChangeReturn ret = GST_STATE_CHANGE_FAILURE; + GstPngDec *pngdec = NULL; + + pngdec = GST_PNGDEC (element); + + switch (transition) { + case GST_STATE_CHANGE_READY_TO_PAUSED: + gst_pngdec_libpng_init (pngdec); + break; + case GST_STATE_CHANGE_PAUSED_TO_READY: + gst_pngdec_libpng_clear (pngdec); + break; + default: + break; } - if (pngdec->width != width || - pngdec->height != height || - pngdec->color_type != pngdec->info->color_type) { - GstCaps *caps, *templ, *res; - gboolean ret; - gint bpp; - - GST_LOG ("this is a %dx%d PNG image", width, height); - pngdec->width = width; - pngdec->height = height; - pngdec->color_type = pngdec->info->color_type; - - switch (pngdec->color_type) { - case PNG_COLOR_TYPE_RGB: - GST_LOG ("we have no alpha channel, depth is 24 bits"); - bpp = 24; - break; - case PNG_COLOR_TYPE_RGB_ALPHA: - GST_LOG ("we have an alpha channel, depth is 32 bits"); - bpp = 32; - break; - default: - GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL), - ("pngdec does not support grayscale or paletted data yet")); - ret = GST_FLOW_UNEXPECTED; - goto beach; - } - - caps = gst_caps_new_simple ("video/x-raw-rgb", - "width", G_TYPE_INT, width, - "height", G_TYPE_INT, height, - "bpp", G_TYPE_INT, bpp, "framerate", G_TYPE_DOUBLE, pngdec->fps, NULL); - - templ = gst_caps_copy (gst_pad_template_get_caps - (gst_static_pad_template_get (&gst_pngdec_src_pad_template))); + ret = parent_class->change_state (element, transition); - res = gst_caps_intersect (templ, caps); - gst_caps_unref (caps); - gst_caps_unref (templ); - { - gchar *caps_str = gst_caps_to_string (res); + return ret; +} - GST_LOG ("intersecting caps with template gave %s", caps_str); - g_free (caps_str); - } - ret = gst_pad_set_caps (pngdec->srcpad, res); - gst_caps_unref (res); - - if (!ret) { - gst_buffer_unref (buf); - png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo); - GST_ELEMENT_ERROR (pngdec, CORE, NEGOTIATION, (NULL), (NULL)); - ret = GST_FLOW_UNEXPECTED; - goto beach; - } - } +/* this function gets called when we activate ourselves in push mode. */ +static gboolean +gst_pngdec_sink_activate_push (GstPad * sinkpad, gboolean active) +{ + GstPngDec *pngdec; - rows = (png_bytep *) g_malloc (sizeof (png_bytep) * height); + pngdec = GST_PNGDEC (GST_OBJECT_PARENT (sinkpad)); - ret = gst_pad_alloc_buffer (pngdec->srcpad, GST_BUFFER_OFFSET_NONE, - height * ROUND_UP_4 (pngdec->info->rowbytes), - GST_PAD_CAPS (pngdec->srcpad), &out); + pngdec->ret = GST_FLOW_OK; - if (ret != GST_FLOW_OK) { - goto beach; - } + if (active) { + /* Let libpng come back here on error */ + if (setjmp (png_jmpbuf (pngdec->png))) { + GST_LOG ("failed setting up libpng jumb"); + gst_pngdec_libpng_clear (pngdec); + return FALSE; + } - inp = GST_BUFFER_DATA (out); - for (i = 0; i < height; i++) { - rows[i] = inp; - inp += ROUND_UP_4 (pngdec->info->rowbytes); + GST_LOG ("setting up progressive loading callbacks"); + png_set_progressive_read_fn (pngdec->png, pngdec, + user_info_callback, user_endrow_callback, user_end_callback); } - png_read_image (pngdec->png, rows); - free (rows); + return TRUE; +} - png_destroy_info_struct (pngdec->png, &pngdec->info); - png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo); +/* this function gets called when we activate ourselves in pull mode. + * We can perform random access to the resource and we start a task + * to start reading */ +static gboolean +gst_pngdec_sink_activate_pull (GstPad * sinkpad, gboolean active) +{ + GstPngDec *pngdec; - pngdec->buffer_in = NULL; - gst_buffer_unref (buf); + pngdec = GST_PNGDEC (GST_OBJECT_PARENT (sinkpad)); - /* Pushing */ - GST_LOG ("pushing our raw RGB frame of %d bytes", GST_BUFFER_SIZE (out)); - ret = gst_pad_push (pngdec->srcpad, out); + if (active) { + return gst_pad_start_task (sinkpad, (GstTaskFunction) gst_pngdec_task, + sinkpad); + } else { + return gst_pad_stop_task (sinkpad); + } +} -beach: - return ret; +/* this function is called when the pad is activated and should start + * processing data. + * + * We check if we can do random access to decide if we work push or + * pull based. + */ +static gboolean +gst_pngdec_sink_activate (GstPad * sinkpad) +{ + if (gst_pad_check_pull_range (sinkpad)) { + return gst_pad_activate_pull (sinkpad, TRUE); + } else { + return gst_pad_activate_push (sinkpad, TRUE); + } } diff --git a/ext/libpng/gstpngdec.h b/ext/libpng/gstpngdec.h index 62232c48..5f5cdca9 100644 --- a/ext/libpng/gstpngdec.h +++ b/ext/libpng/gstpngdec.h @@ -41,12 +41,18 @@ struct _GstPngDec GstPad *sinkpad, *srcpad; - GstBuffer *buffer_in; + /* Progressive */ + GstBuffer *buffer_out; + GstFlowReturn ret; + png_uint_32 rowbytes; + + /* Pull range */ gint offset; png_structp png; png_infop info; png_infop endinfo; + gboolean setup; gint width; gint height; -- cgit