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avcodec/ac3_parser: add avpriv_ac3_parse_header2() and use it in libavcodec

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The new function has the ability to allocate the structure, allowing it to grow
without needing major bumps

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2014-03-01 01:47:33 +01:00
parent df6d21c1e7
commit eadc21cfe7
3 changed files with 25 additions and 6 deletions
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22
libavcodec/ac3_parser.c
View File

@ -47,9 +47,16 @@ static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
static const uint8_t surround_levels[4] = { 4, 6, 7, 6 }; static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr) int avpriv_ac3_parse_header2(GetBitContext *gbc, AC3HeaderInfo **phdr)
{ {
int frame_size_code; int frame_size_code;
AC3HeaderInfo *hdr;
if (!*phdr)
*phdr = av_mallocz(sizeof(AC3HeaderInfo));
if (!*phdr)
return AVERROR(ENOMEM);
hdr = *phdr;
memset(hdr, 0, sizeof(*hdr)); memset(hdr, 0, sizeof(*hdr));
@ -144,6 +151,15 @@ int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
return 0; return 0;
} }
int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
AC3HeaderInfo tmp, *ptmp = &tmp;
int ret = avpriv_ac3_parse_header2(gbc, &ptmp);
memcpy(hdr, ptmp, ((intptr_t)&tmp.channel_layout) - ((intptr_t)&tmp) + sizeof(uint64_t));
return ret;
}
static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info, static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
int *need_next_header, int *new_frame_start) int *need_next_header, int *new_frame_start)
{ {
@ -152,11 +168,11 @@ static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
uint64_t u64; uint64_t u64;
uint8_t u8[8]; uint8_t u8[8];
} tmp = { av_be2ne64(state) }; } tmp = { av_be2ne64(state) };
AC3HeaderInfo hdr; AC3HeaderInfo hdr, *phdr = &hdr;
GetBitContext gbc; GetBitContext gbc;
init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54); init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
err = avpriv_ac3_parse_header(&gbc, &hdr); err = avpriv_ac3_parse_header2(&gbc, &phdr);
if(err < 0) if(err < 0)
return 0; return 0;

5
libavcodec/ac3_parser.h
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@ -31,11 +31,14 @@
* Parse the header up to the lfeon element, which is the first 52 or 54 bits * Parse the header up to the lfeon element, which is the first 52 or 54 bits
* depending on the audio coding mode. * depending on the audio coding mode.
* @param[in] gbc BitContext containing the first 54 bits of the frame. * @param[in] gbc BitContext containing the first 54 bits of the frame.
* @param[out] hdr Pointer to struct where header info is written. * @param[out] hdr Pointer to Pointer to struct where header info is written.
* will be allocated if NULL
* @return Returns 0 on success, -1 if there is a sync word mismatch, * @return Returns 0 on success, -1 if there is a sync word mismatch,
* -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate) * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
* element is invalid, or -4 if the frmsizecod (bit rate) element is invalid. * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
*/ */
int avpriv_ac3_parse_header2(GetBitContext *gbc, AC3HeaderInfo **hdr);
int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr); int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr);
#endif /* AVCODEC_AC3_PARSER_H */ #endif /* AVCODEC_AC3_PARSER_H */

4
libavcodec/ac3dec.c
View File

@ -274,10 +274,10 @@ static int ac3_parse_header(AC3DecodeContext *s)
*/ */
static int parse_frame_header(AC3DecodeContext *s) static int parse_frame_header(AC3DecodeContext *s)
{ {
AC3HeaderInfo hdr; AC3HeaderInfo hdr, *phdr=&hdr;
int err; int err;
err = avpriv_ac3_parse_header(&s->gbc, &hdr); err = avpriv_ac3_parse_header2(&s->gbc, &phdr);
if (err) if (err)
return err; return err;