[libdvdcss-devel] [PATCH 2/2] Add dvdcss_open_stream() API function
Diego Biurrun
diego at biurrun.de
Fri Nov 7 19:34:13 CET 2014
From: Thomas Guillem <tom at gllm.fr>
This allows opening a DVD device using external read/seek callbacks.
Signed-off-by: Diego Biurrun <diego at biurrun.de>
---
Now with *actual* doxygen updates and some more constness.
NEWS | 2 +
src/device.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++-
src/dvdcss/dvdcss.h | 15 +++++++
src/libdvdcss.c | 30 ++++++++++++++
src/libdvdcss.h | 3 ++
5 files changed, 158 insertions(+), 2 deletions(-)
diff --git a/NEWS b/NEWS
index 61c7b58..3896654 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,8 @@ Changes since 1.3.0:
Windows NT 4.0 SP4 with IE 5.0 is now required.
* Replace BeOS support by Haiku support.
* dvdcss_error() now returns "const char *" instad of "char *".
+ * Add dvdcss_open_stream() to public API. This allows installing custom
+ callback functions for accessing DVD, e.g. over the network.
* Miscellaneous cleanups to code, documentation, build system.
diff --git a/src/device.c b/src/device.c
index 5030984..c14c583 100644
--- a/src/device.c
+++ b/src/device.c
@@ -82,6 +82,10 @@ static int libc_seek ( dvdcss_t, int );
static int libc_read ( dvdcss_t, void *, int );
static int libc_readv ( dvdcss_t, const struct iovec *, int );
+static int stream_seek ( dvdcss_t, int );
+static int stream_read ( dvdcss_t, void *, int );
+static int stream_readv ( dvdcss_t, const struct iovec *, int );
+
#ifdef WIN32
static int win2k_open ( dvdcss_t, const char * );
static int win2k_seek ( dvdcss_t, int );
@@ -98,6 +102,9 @@ static int os2_open ( dvdcss_t, const char * );
int dvdcss_use_ioctls( dvdcss_t dvdcss )
{
+ if( dvdcss->p_stream )
+ return 0;
+
#if defined( WIN32 )
if( dvdcss->b_file )
{
@@ -189,8 +196,8 @@ void dvdcss_check_device ( dvdcss_t dvdcss )
int i, i_fd;
#endif
- /* If the device name is non-null, return */
- if( dvdcss->psz_device[0] )
+ /* If the device name is non-NULL or stream is set, return. */
+ if( dvdcss->psz_device[0] || dvdcss->p_stream )
{
return;
}
@@ -347,6 +354,16 @@ int dvdcss_open_device ( dvdcss_t dvdcss )
print_debug( dvdcss, "opening target `%s'", psz_device );
+ /* if callback functions are initialized */
+ if( dvdcss->p_stream )
+ {
+ print_debug( dvdcss, "using stream API for access" );
+ dvdcss->pf_seek = stream_seek;
+ dvdcss->pf_read = stream_read;
+ dvdcss->pf_readv = stream_readv;
+ return 0;
+ }
+
#if defined( WIN32 )
dvdcss->b_file = 1;
/* If device is "X:" or "X:\", we are not actually opening a file. */
@@ -562,6 +579,31 @@ static int libc_seek( dvdcss_t dvdcss, int i_blocks )
return dvdcss->i_pos;
}
+static int stream_seek( dvdcss_t dvdcss, int i_blocks )
+{
+ off_t i_seek = i_blocks * DVDCSS_BLOCK_SIZE;
+
+ if( !dvdcss->p_stream_cb->pf_seek )
+ return -1;
+
+ if( dvdcss->i_pos == i_blocks )
+ {
+ /* We are already in position */
+ return i_blocks;
+ }
+
+ if( dvdcss->p_stream_cb->pf_seek( dvdcss->p_stream, i_seek ) != 0 )
+ {
+ print_error( dvdcss, "seek error" );
+ dvdcss->i_pos = -1;
+ return -1;
+ }
+
+ dvdcss->i_pos = i_blocks;
+
+ return dvdcss->i_pos;
+}
+
#if defined( WIN32 )
static int win2k_seek( dvdcss_t dvdcss, int i_blocks )
{
@@ -630,6 +672,46 @@ static int libc_read ( dvdcss_t dvdcss, void *p_buffer, int i_blocks )
return i_ret_blocks;
}
+static int stream_read ( dvdcss_t dvdcss, void *p_buffer, int i_blocks )
+{
+ off_t i_size, i_ret, i_ret_blocks;
+
+ i_size = i_blocks * DVDCSS_BLOCK_SIZE;
+
+ if( !dvdcss->p_stream_cb->pf_read )
+ return -1;
+
+ i_ret = dvdcss->p_stream_cb->pf_read( dvdcss->p_stream, p_buffer, i_size );
+
+ if( i_ret < 0 )
+ {
+ print_error( dvdcss, "read error" );
+ dvdcss->i_pos = -1;
+ return i_ret;
+ }
+
+ i_ret_blocks = i_ret / DVDCSS_BLOCK_SIZE;
+
+ /* Handle partial reads */
+ if( i_ret != i_size )
+ {
+ int i_seek;
+
+ dvdcss->i_pos = -1;
+ i_seek = stream_seek( dvdcss, i_ret_blocks );
+ if( i_seek < 0 )
+ {
+ return i_seek;
+ }
+
+ /* We have to return now so that i_pos isn't clobbered */
+ return i_ret_blocks;
+ }
+
+ dvdcss->i_pos += i_ret_blocks;
+ return i_ret_blocks;
+}
+
#if defined( WIN32 )
static int win2k_read ( dvdcss_t dvdcss, void *p_buffer, int i_blocks )
{
@@ -722,6 +804,30 @@ static int libc_readv ( dvdcss_t dvdcss, const struct iovec *p_iovec,
#endif
}
+/*****************************************************************************
+ * stream_readv: vectored read
+ *****************************************************************************/
+static int stream_readv ( dvdcss_t dvdcss, const struct iovec *p_iovec,
+ int i_blocks )
+{
+ int i_read;
+
+ if( !dvdcss->p_stream_cb->pf_readv )
+ return -1;
+
+ i_read = dvdcss->p_stream_cb->pf_readv( dvdcss->p_stream, p_iovec,
+ i_blocks );
+
+ if( i_read < 0 )
+ {
+ dvdcss->i_pos = -1;
+ return i_read;
+ }
+
+ dvdcss->i_pos += i_read / DVDCSS_BLOCK_SIZE;
+ return i_read / DVDCSS_BLOCK_SIZE;
+}
+
#if defined( WIN32 )
/*****************************************************************************
* win2k_readv: vectored read using ReadFile for Win2K
diff --git a/src/dvdcss/dvdcss.h b/src/dvdcss/dvdcss.h
index ea62b8b..a630107 100644
--- a/src/dvdcss/dvdcss.h
+++ b/src/dvdcss/dvdcss.h
@@ -31,6 +31,8 @@
#define DVDCSS_DVDCSS_H 1
#endif
+#include <stdint.h>
+
#ifdef __cplusplus
extern "C" {
#endif
@@ -38,6 +40,17 @@ extern "C" {
/** Library instance handle, to be used for each library call. */
typedef struct dvdcss_s* dvdcss_t;
+/** Set of callbacks to access DVDs in custom ways. */
+typedef struct dvdcss_stream_cb
+{
+ /** custom seek callback */
+ int ( *pf_seek ) ( void *p_stream, uint64_t i_pos);
+ /** custom read callback */
+ int ( *pf_read ) ( void *p_stream, void *buffer, int i_read);
+ /** custom vectored read callback */
+ int ( *pf_readv ) ( void *p_stream, const void *p_iovec, int i_blocks);
+} dvdcss_stream_cb;
+
/** The block size of a DVD. */
#define DVDCSS_BLOCK_SIZE 2048
@@ -73,6 +86,8 @@ typedef struct dvdcss_s* dvdcss_t;
* Exported prototypes.
*/
LIBDVDCSS_EXPORT dvdcss_t dvdcss_open ( const char *psz_target );
+LIBDVDCSS_EXPORT dvdcss_t dvdcss_open_stream( void *p_stream,
+ dvdcss_stream_cb *p_stream_cb );
LIBDVDCSS_EXPORT int dvdcss_close ( dvdcss_t );
LIBDVDCSS_EXPORT int dvdcss_seek ( dvdcss_t,
int i_blocks,
diff --git a/src/libdvdcss.c b/src/libdvdcss.c
index 4c19c6d..b90243d 100644
--- a/src/libdvdcss.c
+++ b/src/libdvdcss.c
@@ -145,6 +145,8 @@
#define MANUFACTURING_DATE_LENGTH 16
+static dvdcss_t dvdcss_open_common ( const char *psz_target, void *p_stream,
+ dvdcss_stream_cb *p_stream_cb );
static void set_verbosity( dvdcss_t dvdcss )
{
const char *psz_verbose = getenv( "DVDCSS_VERBOSE" );
@@ -452,12 +454,37 @@ static void init_cache( dvdcss_t dvdcss )
*/
LIBDVDCSS_EXPORT dvdcss_t dvdcss_open ( const char *psz_target )
{
+ return dvdcss_open_common( psz_target, NULL, NULL );
+}
+
+/**
+ * \brief Open a DVD device using dvdcss_stream_cb.
+ *
+ * \param p_stream a private handle used by p_stream_cb
+ * \param p_stream_cb a struct containing seek and read functions
+ * \return a handle to a dvdcss instance or NULL on error.
+ *
+ * \see dvdcss_open()
+ */
+LIBDVDCSS_EXPORT dvdcss_t dvdcss_open_stream ( void *p_stream,
+ dvdcss_stream_cb *p_stream_cb )
+{
+ return dvdcss_open_common( NULL, p_stream, p_stream_cb );
+}
+
+static dvdcss_t dvdcss_open_common ( const char *psz_target, void *p_stream,
+ dvdcss_stream_cb *p_stream_cb )
+{
int i_ret;
#ifdef DVDCSS_RAW_OPEN
const char *psz_raw_device = getenv( "DVDCSS_RAW_DEVICE" );
#endif
+ if( psz_target == NULL &&
+ ( p_stream == NULL || p_stream_cb == NULL ) )
+ return NULL;
+
/* Allocate the library structure. */
dvdcss_t dvdcss = malloc( sizeof( *dvdcss ) );
if( dvdcss == NULL )
@@ -475,6 +502,9 @@ LIBDVDCSS_EXPORT dvdcss_t dvdcss_open ( const char *psz_target )
dvdcss->i_method = DVDCSS_METHOD_KEY;
dvdcss->psz_cachefile[0] = '\0';
+ dvdcss->p_stream = p_stream;
+ dvdcss->p_stream_cb = p_stream_cb;
+
/* Set library verbosity from DVDCSS_VERBOSE environment variable. */
set_verbosity( dvdcss );
diff --git a/src/libdvdcss.h b/src/libdvdcss.h
index 2d5400e..0565132 100644
--- a/src/libdvdcss.h
+++ b/src/libdvdcss.h
@@ -80,6 +80,9 @@ struct dvdcss_s
int i_readv_buf_size;
#endif /* WIN32 */
+ void *p_stream;
+ dvdcss_stream_cb *p_stream_cb;
+
#ifdef DVDCSS_RAW_OPEN
int i_raw_fd;
#endif
--
2.1.0
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