1 /* GStreamer bz2 encoder
2  * Copyright (C) 2006 Lutz Müller <lutz topfrose de>
3 
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Library General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Library General Public License for more details.
13  *
14  * You should have received a copy of the GNU Library General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
17  * Boston, MA 02110-1301, USA.
18  */
19 #ifdef HAVE_CONFIG_H
20 #include "config.h"
21 #endif
22 #include "gstbz2enc.h"
23 
24 #include <bzlib.h>
25 #include <string.h>
26 
27 GST_DEBUG_CATEGORY_STATIC (bz2enc_debug);
28 #define GST_CAT_DEFAULT bz2enc_debug
29 
30 static GstStaticPadTemplate sink_template =
31 GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
32     GST_STATIC_CAPS ("ANY"));
33 static GstStaticPadTemplate src_template =
34 GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
35     GST_STATIC_CAPS ("application/x-bzip"));
36 
37 #define DEFAULT_BLOCK_SIZE 6
38 #define DEFAULT_BUFFER_SIZE 1024
39 
40 enum
41 {
42   PROP_0,
43   PROP_BLOCK_SIZE,
44   PROP_BUFFER_SIZE
45 };
46 
47 struct _GstBz2enc
48 {
49   GstElement parent;
50 
51   GstPad *sink;
52   GstPad *src;
53 
54   /* Properties */
55   guint block_size;
56   guint buffer_size;
57 
58   gboolean ready;
59   bz_stream stream;
60   guint64 offset;
61 };
62 
63 struct _GstBz2encClass
64 {
65   GstElementClass parent_class;
66 };
67 
68 #define gst_bz2enc_parent_class parent_class
69 G_DEFINE_TYPE (GstBz2enc, gst_bz2enc, GST_TYPE_ELEMENT);
70 
71 static void
gst_bz2enc_compress_end(GstBz2enc * b)72 gst_bz2enc_compress_end (GstBz2enc * b)
73 {
74   g_return_if_fail (GST_IS_BZ2ENC (b));
75 
76   if (b->ready) {
77     BZ2_bzCompressEnd (&b->stream);
78     memset (&b->stream, 0, sizeof (b->stream));
79     b->ready = FALSE;
80   }
81 }
82 
83 static void
gst_bz2enc_compress_init(GstBz2enc * b)84 gst_bz2enc_compress_init (GstBz2enc * b)
85 {
86   g_return_if_fail (GST_IS_BZ2ENC (b));
87 
88   gst_bz2enc_compress_end (b);
89   b->offset = 0;
90   switch (BZ2_bzCompressInit (&b->stream, b->block_size, 0, 0)) {
91     case BZ_OK:
92       b->ready = TRUE;
93       return;
94     default:
95       b->ready = FALSE;
96       GST_ELEMENT_ERROR (b, CORE, FAILED, (NULL),
97           ("Failed to start compression."));
98       return;
99   }
100 }
101 
102 static gboolean
gst_bz2enc_event(GstPad * pad,GstObject * parent,GstEvent * e)103 gst_bz2enc_event (GstPad * pad, GstObject * parent, GstEvent * e)
104 {
105   GstBz2enc *b;
106   gboolean ret;
107 
108   b = GST_BZ2ENC (parent);
109   switch (GST_EVENT_TYPE (e)) {
110     case GST_EVENT_EOS:{
111       GstFlowReturn flow = GST_FLOW_OK;
112       int r = BZ_FINISH_OK;
113 
114       do {
115         GstBuffer *out;
116         GstMapInfo omap;
117         guint n;
118 
119         out = gst_buffer_new_and_alloc (b->buffer_size);
120 
121         gst_buffer_map (out, &omap, GST_MAP_WRITE);
122         b->stream.next_out = (char *) omap.data;
123         b->stream.avail_out = omap.size;
124         r = BZ2_bzCompress (&b->stream, BZ_FINISH);
125         gst_buffer_unmap (out, &omap);
126         if ((r != BZ_FINISH_OK) && (r != BZ_STREAM_END)) {
127           GST_ELEMENT_ERROR (b, STREAM, ENCODE, (NULL),
128               ("Failed to finish to compress (error code %i).", r));
129           gst_buffer_unref (out);
130           break;
131         }
132 
133         n = gst_buffer_get_size (out);
134         if (b->stream.avail_out >= n) {
135           gst_buffer_unref (out);
136           break;
137         }
138 
139         gst_buffer_resize (out, 0, n - b->stream.avail_out);
140         n = gst_buffer_get_size (out);
141         GST_BUFFER_OFFSET (out) = b->stream.total_out_lo32 - n;
142 
143         flow = gst_pad_push (b->src, out);
144 
145         if (flow != GST_FLOW_OK) {
146           GST_DEBUG_OBJECT (b, "push on EOS failed: %s",
147               gst_flow_get_name (flow));
148           break;
149         }
150       } while (r != BZ_STREAM_END);
151 
152       ret = gst_pad_event_default (pad, parent, e);
153 
154       if (r != BZ_STREAM_END || flow != GST_FLOW_OK)
155         ret = FALSE;
156 
157       gst_bz2enc_compress_init (b);
158       break;
159     }
160     default:
161       ret = gst_pad_event_default (pad, parent, e);
162       break;
163   }
164 
165   return ret;
166 }
167 
168 static GstFlowReturn
gst_bz2enc_chain(GstPad * pad,GstObject * parent,GstBuffer * in)169 gst_bz2enc_chain (GstPad * pad, GstObject * parent, GstBuffer * in)
170 {
171   GstFlowReturn flow = GST_FLOW_OK;
172   GstBuffer *out;
173   GstBz2enc *b;
174   guint n;
175   int bz2_ret;
176   GstMapInfo map = GST_MAP_INFO_INIT, omap;
177 
178   b = GST_BZ2ENC (parent);
179 
180   if (!b->ready)
181     goto not_ready;
182 
183   gst_buffer_map (in, &map, GST_MAP_READ);
184   b->stream.next_in = (char *) map.data;
185   b->stream.avail_in = map.size;
186   while (b->stream.avail_in) {
187     out = gst_buffer_new_and_alloc (b->buffer_size);
188 
189     gst_buffer_map (out, &omap, GST_MAP_WRITE);
190     b->stream.next_out = (char *) omap.data;
191     b->stream.avail_out = omap.size;
192     bz2_ret = BZ2_bzCompress (&b->stream, BZ_RUN);
193     gst_buffer_unmap (out, &omap);
194     if (bz2_ret != BZ_RUN_OK)
195       goto compress_error;
196 
197     n = gst_buffer_get_size (out);
198     if (b->stream.avail_out >= n) {
199       gst_buffer_unref (out);
200       break;
201     }
202 
203     gst_buffer_resize (out, 0, n - b->stream.avail_out);
204     n = gst_buffer_get_size (out);
205     GST_BUFFER_OFFSET (out) = b->stream.total_out_lo32 - n;
206 
207     flow = gst_pad_push (b->src, out);
208 
209     if (flow != GST_FLOW_OK)
210       break;
211 
212     b->offset += n;
213   }
214 
215 done:
216 
217   gst_buffer_unmap (in, &map);
218   gst_buffer_unref (in);
219   return flow;
220 
221 /* ERRORS */
222 not_ready:
223   {
224     GST_ELEMENT_ERROR (b, LIBRARY, FAILED, (NULL), ("Compressor not ready."));
225     flow = GST_FLOW_FLUSHING;
226     goto done;
227   }
228 compress_error:
229   {
230     GST_ELEMENT_ERROR (b, STREAM, ENCODE, (NULL),
231         ("Failed to compress data (error code %i)", bz2_ret));
232     gst_bz2enc_compress_init (b);
233     gst_buffer_unref (out);
234     flow = GST_FLOW_ERROR;
235     goto done;
236   }
237 }
238 
239 static void
gst_bz2enc_init(GstBz2enc * b)240 gst_bz2enc_init (GstBz2enc * b)
241 {
242   b->sink = gst_pad_new_from_static_template (&sink_template, "sink");
243   gst_pad_set_chain_function (b->sink, GST_DEBUG_FUNCPTR (gst_bz2enc_chain));
244   gst_pad_set_event_function (b->sink, GST_DEBUG_FUNCPTR (gst_bz2enc_event));
245   gst_element_add_pad (GST_ELEMENT (b), b->sink);
246 
247   b->src = gst_pad_new_from_static_template (&src_template, "src");
248   gst_pad_set_caps (b->src, gst_static_pad_template_get_caps (&src_template));
249   gst_pad_use_fixed_caps (b->src);
250   gst_element_add_pad (GST_ELEMENT (b), b->src);
251 
252   b->block_size = DEFAULT_BLOCK_SIZE;
253   b->buffer_size = DEFAULT_BUFFER_SIZE;
254   gst_bz2enc_compress_init (b);
255 }
256 
257 static void
gst_bz2enc_finalize(GObject * object)258 gst_bz2enc_finalize (GObject * object)
259 {
260   GstBz2enc *b = GST_BZ2ENC (object);
261 
262   gst_bz2enc_compress_end (b);
263 
264   G_OBJECT_CLASS (parent_class)->finalize (object);
265 }
266 
267 static void
gst_bz2enc_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)268 gst_bz2enc_get_property (GObject * object, guint prop_id,
269     GValue * value, GParamSpec * pspec)
270 {
271   GstBz2enc *b = GST_BZ2ENC (object);
272 
273   switch (prop_id) {
274     case PROP_BLOCK_SIZE:
275       g_value_set_uint (value, b->block_size);
276       break;
277     case PROP_BUFFER_SIZE:
278       g_value_set_uint (value, b->buffer_size);
279       break;
280     default:
281       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
282   }
283 }
284 
285 static void
gst_bz2enc_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)286 gst_bz2enc_set_property (GObject * object, guint prop_id,
287     const GValue * value, GParamSpec * pspec)
288 {
289   GstBz2enc *b = GST_BZ2ENC (object);
290 
291   switch (prop_id) {
292     case PROP_BLOCK_SIZE:
293       b->block_size = g_value_get_uint (value);
294       gst_bz2enc_compress_init (b);
295       break;
296     case PROP_BUFFER_SIZE:
297       b->buffer_size = g_value_get_uint (value);
298       break;
299     default:
300       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
301   }
302 }
303 
304 static void
gst_bz2enc_class_init(GstBz2encClass * klass)305 gst_bz2enc_class_init (GstBz2encClass * klass)
306 {
307   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
308   GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
309 
310   gobject_class->finalize = gst_bz2enc_finalize;
311   gobject_class->set_property = gst_bz2enc_set_property;
312   gobject_class->get_property = gst_bz2enc_get_property;
313 
314   g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_BLOCK_SIZE,
315       g_param_spec_uint ("block-size", "Block size", "Block size",
316           1, 9, DEFAULT_BLOCK_SIZE,
317           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
318   g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_BUFFER_SIZE,
319       g_param_spec_uint ("buffer-size", "Buffer size", "Buffer size",
320           1, G_MAXUINT, DEFAULT_BUFFER_SIZE,
321           G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
322 
323   gst_element_class_add_static_pad_template (gstelement_class, &sink_template);
324   gst_element_class_add_static_pad_template (gstelement_class, &src_template);
325   gst_element_class_set_static_metadata (gstelement_class, "BZ2 encoder",
326       "Codec/Encoder", "Compresses streams",
327       "Lutz Mueller <lutz@users.sourceforge.net>");
328 
329   GST_DEBUG_CATEGORY_INIT (bz2enc_debug, "bz2enc", 0, "BZ2 compressor");
330 }
331