On Fri, 12 Jun 2009 15:21:38 -0400, Stas Oskin <stas.os...@gmail.com>
wrote:
Hi.
I have externally encoded MPEG4 data coming to me from a RTSP source. I'm
basically receiving just arrays of bytes per each frame + some info like
frame type and PTS.
I need to decode this to JPEG - any idea how I do it with FFMPEG?
Thanks in advance!
If you're using C++, you might find the following helpful. I wrote it so
that I can just make subclasses of a CustomIOContext class, and then get a
string from an instance of it to pass to av_open_input_file. (yess, I'm
passing a pointer as a string of hex in the filename, hehe)
class TCustomIOContext {
protected:
virtual int url_open(URLContext *h, int flags) { return -1; }
virtual int url_read(URLContext *h, unsigned char *buf, int size) {
return -1; }
virtual int url_write(URLContext *h, unsigned char *buf, int size) {
return -1; }
virtual int64_t url_seek(URLContext *h, int64_t pos, int whence) {
return -1; }
virtual int url_close(URLContext *h) { return -1; }
virtual int url_read_pause(URLContext *h, int pause) { return -1; }
virtual int64_t url_read_seek(URLContext *h, int stream_index, int64_t
timestamp, int flags) { return -1; }
virtual int url_get_file_handle(URLContext *h) { return -1; }
friend struct TCustIoCaller;
public:
TCustomIOContext() {}
virtual ~TCustomIOContext() {}
std::string getLibavUrl();
};
struct TCustIoCaller {
static int open(URLContext *c, const char *filename, int flags);
static int read(URLContext *c, unsigned char *buf, int size) {
return ((TCustomIOContext*)c->priv_data)->url_read(c, buf, size);
}
static int write(URLContext *c, unsigned char *buf, int size) {
return ((TCustomIOContext*)c->priv_data)->url_write(c, buf, size);
}
static int64_t seek(URLContext *c, int64_t pos, int whence) {
return ((TCustomIOContext*)c->priv_data)->url_seek(c, pos, whence);
}
static int close(URLContext *c) {
return ((TCustomIOContext*)c->priv_data)->url_close(c);
}
static int read_pause(URLContext *c, int pause) {
return ((TCustomIOContext*)c->priv_data)->url_read_pause(c, pause);
}
static int64_t read_seek(URLContext *c, int stream_index, int64_t
timestamp, int flags) {
return ((TCustomIOContext*)c->priv_data)->url_read_seek(c,
stream_index, timestamp, flags);
}
static int get_file_handle(URLContext *c) {
return ((TCustomIOContext*)c->priv_data)->url_get_file_handle(c);
}
static string genUrl(TCustomIOContext *cx) {
return IUI::StrFormat("%s:%p", protocol.name, cx);
}
static URLProtocol protocol;
TCustIoCaller() { av_register_protocol(&protocol); }
} register_custio;
URLProtocol TCustIoCaller::protocol = {
"CustomIOContext",
TCustIoCaller::open, TCustIoCaller::read, TCustIoCaller::write,
TCustIoCaller::seek, TCustIoCaller::close,
NULL,
TCustIoCaller::read_pause, TCustIoCaller::read_seek//,
TCustIoCaller::get_file_handle
};
int TCustIoCaller::open(URLContext *c, const char *filename, int flags) {
char* lastChar;
int prefixLen= strlen(protocol.name);
if (strncmp(protocol.name, filename, prefixLen) != 0) return -1;
if (strncmp(":0x", filename+prefixLen, 3) != 0) return -1;
uint64_t ptr_val= strtoll(filename + prefixLen+3, &lastChar, 16);
if ((lastChar == filename + prefixLen) || *lastChar != '\0' ||
!ptr_val)
return -1;
TCustomIOContext *ccx= (TCustomIOContext*) (void*) ptr_val;
c->priv_data= ccx;
return ccx->url_open(c, flags);
}
--
Michael Conrad
IntelliTree Solutions llc.
513-552-6362
mcon...@intellitree.com
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