parsers: improve AAC/LATM parser
This commit is contained in:
Jaroslav Kysela
parent
cd1f081909
commit
cc1fbb0202
6 changed files with 169 additions and 107 deletions
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@ -40,23 +40,10 @@ init_wbits(bitstream_t *bs, uint8_t *data, int bits)
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bs->len = bits;
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}
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void
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skip_bits(bitstream_t *bs, int num)
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{
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bs->offset += num;
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}
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int
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bs_eof(const bitstream_t *bs)
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{
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return bs->offset >= bs->len;
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}
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unsigned int
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read_bits(bitstream_t *bs, int num)
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{
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int r = 0;
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unsigned int r = 0;
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while(num > 0) {
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if(bs->offset >= bs->len)
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@ -73,9 +60,22 @@ read_bits(bitstream_t *bs, int num)
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}
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unsigned int
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read_bits1(bitstream_t *bs)
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show_bits(bitstream_t *bs, int num)
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{
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return read_bits(bs, 1);
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unsigned int r = 0, offset = bs->offset;
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while(num > 0) {
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if(offset >= bs->len)
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return 0;
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num--;
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if(bs->rdata[offset / 8] & (1 << (7 - (offset & 7))))
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r |= 1 << num;
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offset++;
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}
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return r;
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}
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unsigned int
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@ -106,13 +106,6 @@ read_golomb_se(bitstream_t *bs)
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}
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unsigned int
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remaining_bits(bitstream_t *bs)
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{
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return bs->len - bs->offset;
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}
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void
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put_bits(bitstream_t *bs, int val, int num)
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{
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@ -26,7 +26,8 @@ typedef struct bitstream {
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int len;
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} bitstream_t;
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void skip_bits(bitstream_t *bs, int num);
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static inline void skip_bits(bitstream_t *bs, int num)
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{ bs->offset += num; }
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void init_rbits(bitstream_t *bs, const uint8_t *data, int bits);
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@ -34,16 +35,21 @@ void init_wbits(bitstream_t *bs, uint8_t *data, int bits);
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unsigned int read_bits(bitstream_t *gb, int num);
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unsigned int read_bits1(bitstream_t *gb);
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unsigned int show_bits(bitstream_t *gb, int num);
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static inline unsigned int read_bits1(bitstream_t *gb)
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{ return read_bits(gb, 1); }
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unsigned int read_golomb_ue(bitstream_t *gb);
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signed int read_golomb_se(bitstream_t *gb);
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unsigned int remaining_bits(bitstream_t *gb);
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static inline unsigned int remaining_bits(bitstream_t *gb)
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{ return gb->len - gb->offset; }
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void put_bits(bitstream_t *bs, int val, int num);
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int bs_eof(const bitstream_t *bs);
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static inline int bs_eof(const bitstream_t *bs)
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{ return bs->offset >= bs->len; }
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#endif /* BITSTREAM_H_ */
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@ -40,6 +40,7 @@ typedef struct latm_private {
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int configured;
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int audio_mux_version_A;
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int aot;
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int frame_length_type;
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int sample_rate_index;
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@ -55,74 +56,110 @@ latm_get_value(bitstream_t *bs)
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return read_bits(bs, read_bits(bs, 2) * 8);
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}
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#define AOT_AAC_MAIN 1
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#define AOT_AAC_LC 2
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#define AOT_AAC_SSR 3
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#define AOT_AAC_LTP 4
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#define AOT_SBR 5
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#define AOT_PS 26
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#define AOT_ESCAPE 28
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static void
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static inline int adts_aot(int aot)
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{
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switch (aot) {
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case AOT_AAC_MAIN: return 0;
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case AOT_AAC_LC : return 1;
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case AOT_AAC_SSR : return 2;
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default: return 3; /* reserved or LTP */
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}
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}
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static inline int read_aot(bitstream_t *bs)
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{
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int aot = read_bits(bs, 5);
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if (aot == AOT_ESCAPE)
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aot = read_bits(bs, 6);
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return aot;
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}
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static inline int read_sr(bitstream_t *bs, int *sri)
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{
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*sri = read_bits(bs, 4);
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if (*sri == 0x0f)
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return read_bits(bs, 24);
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else
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return sri_to_rate(*sri);
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}
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static int
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read_audio_specific_config(elementary_stream_t *st, latm_private_t *latm,
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bitstream_t *bs)
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{
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int aot, sr;
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aot = read_bits(bs, 5);
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if ((bs->offset % 8) != 0)
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return -1;
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latm->sample_rate_index = read_bits(bs, 4);
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if(latm->sample_rate_index == 0xf)
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sr = read_bits(bs, 24);
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else
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sr = sri_to_rate(latm->sample_rate_index);
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if(sr == 0)
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return;
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aot = read_aot(bs);
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sr = read_sr(bs, &latm->sample_rate_index);
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latm->channel_config = read_bits(bs, 4);
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st->es_frame_duration = 1024 * 90000 / sr;
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latm->channel_config = read_bits(bs, 4);
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if (aot == 5) { // AOT_SBR
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if (read_bits(bs, 4) == 0xf) { // extensionSamplingFrequencyIndex
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skip_bits(bs, 24);
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}
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aot = read_bits(bs, 5); // this is the main object type (i.e. non-extended)
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if (aot == AOT_SBR ||
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(aot == AOT_PS && !(show_bits(bs, 3) & 3 && !(show_bits(bs, 9) & 0x3f)))) {
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sr = read_sr(bs, &latm->sample_rate_index);
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aot = read_aot(bs); // this is the main object type (i.e. non-extended)
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}
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if(aot != 2)
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return;
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if (sr == 0 || latm->channel_config == 0)
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return -1;
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if (aot != AOT_AAC_MAIN && aot != AOT_AAC_LC &&
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aot != AOT_AAC_SSR && aot != AOT_AAC_LTP)
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return -1;
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latm->aot = aot;
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skip_bits(bs, 1); //framelen_flag
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if(read_bits1(bs)) // depends_on_coder
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if (read_bits1(bs)) // framelen_flag
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return -1;
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if (read_bits1(bs)) // depends_on_coder
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skip_bits(bs, 14);
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if(read_bits(bs, 1)) // ext_flag
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if (read_bits1(bs)) // ext_flag
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skip_bits(bs, 1); // ext3_flag
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return 0;
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}
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static void
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static int
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read_stream_mux_config(elementary_stream_t *st, latm_private_t *latm, bitstream_t *bs)
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{
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int audio_mux_version = read_bits(bs, 1);
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int audio_mux_version = read_bits1(bs);
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latm->audio_mux_version_A = 0;
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if(audio_mux_version) // audioMuxVersion
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latm->audio_mux_version_A = read_bits(bs, 1);
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if(audio_mux_version) // audioMuxVersion
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latm->audio_mux_version_A = read_bits1(bs);
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if(latm->audio_mux_version_A)
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return;
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return 0;
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if(audio_mux_version)
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latm_get_value(bs); // taraFullness
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latm_get_value(bs); // taraFullness
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skip_bits(bs, 1); // allStreamSameTimeFraming = 1
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skip_bits(bs, 6); // numSubFrames = 0
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skip_bits(bs, 4); // numPrograms = 0
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// for each program (which there is only on in DVB)
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skip_bits(bs, 3); // numLayer = 0
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if (read_bits(bs, 4)) // numPrograms = 0
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return -1;
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// for each program (only one in DVB)
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if (read_bits(bs, 3)) // numLayer = 0
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return -1;
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// for each layer (which there is only on in DVB)
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if(!audio_mux_version)
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read_audio_specific_config(st, latm, bs);
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else {
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return;
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// for each layer (which there is only one in DVB)
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if(!audio_mux_version) {
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if (read_audio_specific_config(st, latm, bs) < 0)
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return -1;
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} else {
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return -1;
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#if 0 // see bellow (look for dead code)
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uint32_t ascLen = latm_get_value(bs);
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abort(); // ascLen -= read_audio_specific_config(filter, gb);
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@ -150,24 +187,25 @@ read_stream_mux_config(elementary_stream_t *st, latm_private_t *latm, bitstream_
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break;
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}
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if(read_bits(bs, 1)) { // other data?
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if(read_bits1(bs)) { // other data?
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#if 0 // coverity - dead code - see above
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if(audio_mux_version)
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latm_get_value(bs); // other_data_bits
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latm_get_value(bs); // other_data_bits
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else
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#endif
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{
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int esc;
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do {
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esc = read_bits(bs, 1);
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esc = read_bits1(bs);
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skip_bits(bs, 8);
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} while (esc);
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}
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}
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if(read_bits(bs, 1)) // crc present?
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skip_bits(bs, 8); // config_crc
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if(read_bits1(bs)) // crc present?
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skip_bits(bs, 8); // config_crc
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latm->configured = 1;
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return 0;
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}
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/**
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@ -188,7 +226,8 @@ parse_latm_audio_mux_element(service_t *t, elementary_stream_t *st,
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latm = st->es_priv = calloc(1, sizeof(latm_private_t));
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if(!read_bits1(&bs))
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read_stream_mux_config(st, latm, &bs);
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if (read_stream_mux_config(st, latm, &bs) < 0)
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return NULL;
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if(!latm->configured)
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return NULL;
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@ -202,8 +241,7 @@ parse_latm_audio_mux_element(service_t *t, elementary_stream_t *st,
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slot_len += tmp;
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} while (tmp == 255);
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if(slot_len * 8 > remaining_bits(&bs))
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if (slot_len * 8 > remaining_bits(&bs))
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return NULL;
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if(st->es_curdts == PTS_UNSET)
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@ -214,16 +252,16 @@ parse_latm_audio_mux_element(service_t *t, elementary_stream_t *st,
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pkt->pkt_commercial = t->s_tt_commercial_advice;
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pkt->pkt_duration = st->es_frame_duration;
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pkt->pkt_sri = latm->sample_rate_index;
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pkt->pkt_channels = latm->channel_config;
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pkt->pkt_channels = latm->channel_config == 7 ? 8 : latm->channel_config;
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/* 7 bytes of ADTS header */
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init_wbits(&out, pktbuf_ptr(pkt->pkt_payload), 56);
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init_wbits(&out, pktbuf_ptr(pkt->pkt_payload), 7 * 8);
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put_bits(&out, 0xfff, 12); // Sync marker
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put_bits(&out, 1, 1); // ID 0 = MPEG 4, 1 = MPEG 2
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put_bits(&out, 0, 1); // ID 0 = MPEG 4, 1 = MPEG 2
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put_bits(&out, 0, 2); // Layer
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put_bits(&out, 1, 1); // Protection absent
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put_bits(&out, 2, 2); // AOT, 2 = AAC LC (for MPEG 2 bit)
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put_bits(&out, adts_aot(latm->aot), 2);
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put_bits(&out, latm->sample_rate_index, 4);
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put_bits(&out, 1, 1); // Private bit
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put_bits(&out, latm->channel_config, 3);
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@ -233,7 +271,7 @@ parse_latm_audio_mux_element(service_t *t, elementary_stream_t *st,
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put_bits(&out, 1, 1); // Copyright identification bit
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put_bits(&out, 1, 1); // Copyright identification start
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put_bits(&out, slot_len + 7, 13);
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put_bits(&out, 0, 11); // Buffer fullness
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put_bits(&out, 0x7ff, 11); // Buffer fullness
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put_bits(&out, 0, 2); // RDB in frame
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assert(remaining_bits(&out) == 0);
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@ -227,35 +227,48 @@ static void
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parse_aac(service_t *t, elementary_stream_t *st, const uint8_t *data,
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int len, int start)
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{
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int l, muxlen, p;
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int l, muxlen, p, hdr = 0;
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th_pkt_t *pkt;
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int64_t olddts = PTS_UNSET, oldpts = PTS_UNSET;
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int64_t newdts = PTS_UNSET, newpts = PTS_UNSET;
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if(start) {
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/* Payload unit start */
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st->es_parser_state = 1;
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st->es_parser_ptr = 0;
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sbuf_reset(&st->es_buf, 4000);
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if(st->es_parser_state == 0) {
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if (start) {
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/* Payload unit start */
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st->es_parser_state = 1;
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st->es_parser_ptr = 0;
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sbuf_reset(&st->es_buf, 4000);
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} else {
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return;
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}
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}
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if(st->es_parser_state == 0)
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return;
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if(start) {
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int hlen;
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if(len < 9)
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return;
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olddts = st->es_curdts;
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oldpts = st->es_curpts;
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hlen = parse_pes_header(t, st, data + 6, len - 6);
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if (hlen >= 0 && st->es_buf.sb_ptr) {
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newdts = st->es_curdts;
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newpts = st->es_curpts;
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st->es_curdts = olddts;
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st->es_curpts = oldpts;
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}
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if(hlen < 0)
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return;
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data += 6 + hlen;
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len -= 6 + hlen;
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}
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sbuf_append(&st->es_buf, data, len);
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if(st->es_parser_ptr == 0) {
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int hlen;
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if(st->es_buf.sb_ptr < 9)
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return;
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hlen = parse_pes_header(t, st,
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st->es_buf.sb_data + 6, st->es_buf.sb_ptr - 6);
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if(hlen < 0)
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return;
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st->es_parser_ptr += 6 + hlen;
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}
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p = st->es_parser_ptr;
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p = 0;
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while((l = st->es_buf.sb_ptr - p) > 3) {
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const uint8_t *d = st->es_buf.sb_data + p;
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@ -274,12 +287,17 @@ parse_aac(service_t *t, elementary_stream_t *st, const uint8_t *data,
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st->es_buf.sb_err = 0;
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}
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if (hdr && newdts != PTS_UNSET) {
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st->es_curdts = newdts;
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st->es_curpts = newpts;
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}
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p += muxlen + 3;
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/* ADTS */
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} else if(d[0] == 0xff && (d[1] & 0xf0) == 0xf0) {
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} else if(p == 0 && d[0] == 0xff && (d[1] & 0xf0) == 0xf0) {
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if (l < 7)
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break;
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muxlen = ((uint16_t)(d[3] & 0x03) << 11) | ((uint16_t)d[4] << 3) | (d[5] >> 5);
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if (l < muxlen)
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break;
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@ -288,6 +306,10 @@ parse_aac(service_t *t, elementary_stream_t *st, const uint8_t *data,
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sbuf_append(&st->es_buf_a, d, muxlen);
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parse_mp4a_data(t, st, 1);
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if (hdr && newdts != PTS_UNSET) {
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st->es_curdts = newdts;
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st->es_curpts = newpts;
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}
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p += muxlen;
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/* Wrong bytestream */
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@ -296,7 +318,12 @@ parse_aac(service_t *t, elementary_stream_t *st, const uint8_t *data,
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}
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}
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st->es_parser_ptr = p;
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if (hdr && newdts != PTS_UNSET) {
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st->es_curdts = newdts;
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st->es_curpts = newpts;
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}
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if (p > 0)
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sbuf_cut(&st->es_buf, p);
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}
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@ -549,7 +576,6 @@ static int parse_mp4a(service_t *t, elementary_stream_t *st, size_t ilen,
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return 1;
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}
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||||
const static int mpa_br[16] = {
|
||||
0, 32, 48, 56,
|
||||
64, 80, 96, 112,
|
||||
|
|
@ -850,7 +876,6 @@ parse_pes_header(service_t *t, elementary_stream_t *st,
|
|||
pts = getpts(buf);
|
||||
dts = getpts(buf + 5);
|
||||
|
||||
|
||||
d = (pts - dts) & PTS_MASK;
|
||||
if(d > 180000) // More than two seconds of PTS/DTS delta, probably corrupt
|
||||
pts = dts = PTS_UNSET;
|
||||
|
|
|
|||
|
|
@ -108,7 +108,7 @@ apply_header(streaming_start_component_t *ssc, th_pkt_t *pkt)
|
|||
ssc->ssc_gh = pktbuf_alloc(NULL, 2);
|
||||
uint8_t *d = pktbuf_ptr(ssc->ssc_gh);
|
||||
|
||||
const int profile = 2;
|
||||
const int profile = 2; /* AAC LC */
|
||||
d[0] = (profile << 3) | ((pkt->pkt_sri & 0xe) >> 1);
|
||||
d[1] = ((pkt->pkt_sri & 0x1) << 7) | (pkt->pkt_channels << 3);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -331,10 +331,10 @@ create_adts_header(pktbuf_t *pb, int sri, int channels)
|
|||
init_wbits(&bs, pktbuf_ptr(pb), 56);
|
||||
|
||||
put_bits(&bs, 0xfff, 12); // Sync marker
|
||||
put_bits(&bs, 1, 1); // ID 0 = MPEG 4, 1 = MPEG 2
|
||||
put_bits(&bs, 0, 1); // ID 0 = MPEG 4, 1 = MPEG 2
|
||||
put_bits(&bs, 0, 2); // Layer
|
||||
put_bits(&bs, 1, 1); // Protection absent
|
||||
put_bits(&bs, 2, 2); // AOT, 2 = AAC LC (for MPEG 2 bit)
|
||||
put_bits(&bs, 1, 2); // AOT, 1 = AAC LC
|
||||
put_bits(&bs, sri, 4);
|
||||
put_bits(&bs, 1, 1); // Private bit
|
||||
put_bits(&bs, channels, 3);
|
||||
|
|
@ -344,7 +344,7 @@ create_adts_header(pktbuf_t *pb, int sri, int channels)
|
|||
put_bits(&bs, 1, 1); // Copyright identification bit
|
||||
put_bits(&bs, 1, 1); // Copyright identification start
|
||||
put_bits(&bs, pktbuf_len(pb), 13);
|
||||
put_bits(&bs, 0, 11); // Buffer fullness
|
||||
put_bits(&bs, 0x7ff, 11); // Buffer fullness
|
||||
put_bits(&bs, 0, 2); // RDB in frame
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue