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#include "errno.h"
#include "avcodec.h"
#ifndef MKTAG
#define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
#endif
// private structure used to hide all internal memory allocations
// and structures used for de/encoding - end user should
// never see any complicated structure
typedef struct private_handle
{
AVCodec* avcodec;
AVCodecContext avcontext;
struct private_handle* next;
struct private_handle* prev;
} private_handle_t;
static private_handle_t* handle_first = 0;
static AVCodec* avcodec_find_by_fcc(uint32_t fcc)
{
// translation table
static const struct fcc_to_avcodecid {
enum CodecID codec;
uint32_t list[4]; // maybe we could map more fcc to same codec
} lc[] = {
{ CODEC_ID_H263, { MKTAG('U', '2', '6', '3'), 0 } },
{ CODEC_ID_H263I, { MKTAG('I', '2', '6', '3'), 0 } },
{ CODEC_ID_MSMPEG4V3, { MKTAG('D', 'I', 'V', '3'), 0 } },
{ CODEC_ID_MPEG4, { MKTAG('D', 'I', 'V', 'X'), MKTAG('D', 'X', '5', '0'), 0 } },
{ CODEC_ID_MSMPEG4V2, { MKTAG('M', 'P', '4', '2'), 0 } },
{ CODEC_ID_MJPEG, { MKTAG('M', 'J', 'P', 'G'), 0 } },
{ CODEC_ID_MPEG1VIDEO, { MKTAG('P', 'I', 'M', '1'), 0 } },
{ CODEC_ID_AC3, { 0x2000, 0 } },
{ CODEC_ID_MP2, { 0x50, 0x55, 0 } },
{ CODEC_ID_NONE, {0}}
};
const struct fcc_to_avcodecid* c;
for (c = lc; c->codec != CODEC_ID_NONE; c++)
{
int i = 0;
while (c->list[i] != 0)
if (c->list[i++] == fcc)
return avcodec_find_decoder(c->codec);
}
return NULL;
}
static private_handle_t* create_handle(void)
{
private_handle_t* t = av_malloc(sizeof(private_handle_t));
if (!t)
return NULL;
memset(t, 0, sizeof(*t));
// register and fill
if (!handle_first)
{
avcodec_init();
avcodec_register_all();
handle_first = t;
}
else
{
t->prev = handle_first->next;
handle_first->next = t;
t->next = handle_first;
}
return t;
}
static void destroy_handle(private_handle_t* handle)
{
if (handle)
{
if (handle->avcodec)
{
avcodec_close(&handle->avcontext);
}
av_free(handle);
// count referencies
}
}
int avcodec(void* handle, avc_cmd_t cmd, void* pin, void* pout)
{
AVCodecContext* ctx = handle;
switch (cmd)
{
case AVC_OPEN_BY_NAME:
{
// pin char* codec name
private_handle_t* h = create_handle();
(private_handle_t**)pout = h;
if (!h)
return -ENOMEM;
if (!h->avcodec)
{
destroy_handle(h);
(private_handle_t**)pout = NULL;
return -1;// better error
}
return 0;
}
case AVC_OPEN_BY_CODEC_ID:
{
// pin uint32_t codec fourcc
private_handle_t* h = create_handle();
(private_handle_t**)pout = h;
if (!h)
return -ENOMEM;
if (!h->avcodec)
{
destroy_handle(h);
(private_handle_t**)pout = NULL;
return -1;// better error
}
return 0;
}
case AVC_OPEN_BY_FOURCC:
{
// pin uint32_t codec fourcc
private_handle_t* h = create_handle();
(private_handle_t**)pout = h;
if (!h)
return -ENOMEM;
h->avcodec = avcodec_find_by_fcc((uint32_t) pin);
if (!h->avcodec)
{
destroy_handle(h);
(private_handle_t**)pout = NULL;
return -1;// better error
}
return 0;
}
case AVC_CLOSE:
// uninit part
// eventually close all allocated space if this was last
// instance
destroy_handle(handle);
break;
case AVC_FLUSH:
break;
case AVC_DECODE:
break;
case AVC_ENCODE:
break;
case AVC_GET_VERSION:
(int*) pout = 500;
default:
return -1;
}
return 0;
}
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