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-rw-r--r--src/demuxers/demux_mpgaudio.c133
1 files changed, 63 insertions, 70 deletions
diff --git a/src/demuxers/demux_mpgaudio.c b/src/demuxers/demux_mpgaudio.c
index ee1dc915c..8ccaa9810 100644
--- a/src/demuxers/demux_mpgaudio.c
+++ b/src/demuxers/demux_mpgaudio.c
@@ -126,14 +126,11 @@ typedef struct {
/* current mp3 frame */
mpg_audio_frame_t cur_frame;
-
+
/* next mp3 frame, used when the frame size cannot be computed from the
* current frame header */
mpg_audio_frame_t next_frame;
-
- /* reference mp3 frame, used for extra validation when sync is lost */
- mpg_audio_frame_t ref_frame;
-
+
double cur_time; /* in milliseconds */
off_t mpg_frame_start; /* offset */
@@ -145,9 +142,12 @@ typedef struct {
vbri_header_t *vbri_header;
int found_next_frame:1;
- int has_ref_frame:1;
- off_t free_bitrate_size;
+ int free_bitrate_count;
+ off_t free_bitrate_size; /* use this size if 3 free bitrate frames are encountered */
uint8_t next_header[4];
+ int mpg_version;
+ int mpg_layer;
+ int valid_frames;
} demux_mpgaudio_t ;
@@ -344,7 +344,7 @@ static xing_header_t* parse_xing_header(mpg_audio_frame_t *frame,
if (!xing)
goto exit_error;
- lprintf("Xing header found\n");
+ lprintf("found Xing header\n");
ptr += 4;
if (ptr >= (buf + bufsize - 4)) goto exit_error;
@@ -435,7 +435,7 @@ static vbri_header_t* parse_vbri_header(mpg_audio_frame_t *frame,
if ((ptr + 4) >= (buf + bufsize)) return 0;
lprintf("Checking %08X\n", *ptr);
if (_X_BE_32(ptr) == VBRI_TAG) {
- lprintf("Vbri header found\n");
+ lprintf("found Vbri header\n");
ptr += 4;
if ((ptr + 22) >= (buf + bufsize)) return 0;
@@ -499,24 +499,6 @@ static vbri_header_t* parse_vbri_header(mpg_audio_frame_t *frame,
}
}
-static int check_frame_validity(demux_mpgaudio_t *const this, mpg_audio_frame_t *const frame) {
- int result = 0;
-
- if (this->ref_frame.is_free_bitrate) {
- if ((frame->bitrate == 0) &&
- (this->ref_frame.freq == frame->freq) &&
- (this->ref_frame.version_idx == frame->version_idx) &&
- (this->ref_frame.channel_mode == frame->channel_mode)) {
- result = 1;
- }
- } else {
- if ((this->ref_frame.version_idx == frame->version_idx) &&
- (this->ref_frame.channel_mode == frame->channel_mode)) {
- result = 1;
- }
- }
- return result;
-}
/*
* Parse a mp3 frame paylod
@@ -547,11 +529,12 @@ static int parse_frame_payload(demux_mpgaudio_t *this,
/* compute the payload size */
if (this->cur_frame.size > 0) {
payload_size = this->cur_frame.size - 4;
- } else if (this->free_bitrate_size > 0) {
+ this->free_bitrate_count = 0;
+ } else if (this->free_bitrate_count >= 3) {
payload_size = this->free_bitrate_size + this->cur_frame.padding - 4;
this->cur_frame.size = payload_size + 4;
- payload_size = 0;
} else {
+ this->free_bitrate_count++;
payload_size = 0;
}
@@ -573,7 +556,7 @@ static int parse_frame_payload(demux_mpgaudio_t *this,
int max_size = buf->max_size - 4;
while (payload_size < max_size) {
- len = this->input->read(this->input, &buf->content[payload_size], 1);
+ len = this->input->read(this->input, &buf->content[4 + payload_size], 1);
if (len != 1) {
lprintf("EOF\n");
buf->free_buffer(buf);
@@ -581,28 +564,22 @@ static int parse_frame_payload(demux_mpgaudio_t *this,
}
payload_size += len;
- if (parse_frame_header(&this->next_frame,
- &buf->content[payload_size - 4])) {
- if (check_frame_validity(this, &this->next_frame)) {
- lprintf("found next frame header\n");
- if (this->free_bitrate_size == 0) {
- this->free_bitrate_size = payload_size - this->cur_frame.padding;
- }
- /* don't read the frame header twice */
- this->found_next_frame = 1;
- memcpy(&this->next_header[0], &buf->content[payload_size], 4);
- payload_size -= 4;
- break;
- } else {
- lprintf("invalid frame\n");
+ if (parse_frame_header(&this->next_frame, &buf->content[payload_size])) {
+ lprintf("found next frame header\n");
+
+ if (this->free_bitrate_size == 0) {
+ this->free_bitrate_size = payload_size - this->cur_frame.padding;
}
+
+ /* don't read the frame header twice */
+ this->found_next_frame = 1;
+ memcpy(&this->next_header[0], &buf->content[payload_size], 4);
+ payload_size -= 4;
+ break;
}
}
this->cur_frame.size = payload_size + 4;
- if (this->br == 0) {
- this->br = 8000 * this->cur_frame.size / this->cur_frame.duration;
- }
- this->cur_frame.bitrate = this->br;
+ this->cur_frame.bitrate = 8000 * this->cur_frame.size / this->cur_frame.duration;
lprintf("free bitrate: bitrate: %d, frame size: %d\n", this->br, this->cur_frame.size);
}
@@ -612,11 +589,15 @@ static int parse_frame_payload(demux_mpgaudio_t *this,
this->xing_header = parse_xing_header(&this->cur_frame, buf->content, this->cur_frame.size);
if (this->xing_header) {
buf->free_buffer(buf);
+ xprintf(this->stream->xine, XINE_VERBOSITY_LOG,
+ "demux_mpgaudio: found Xing header at offset %PRId64\n", frame_pos);
return 1;
}
this->vbri_header = parse_vbri_header(&this->cur_frame, buf->content, this->cur_frame.size);
if (this->vbri_header) {
buf->free_buffer(buf);
+ xprintf(this->stream->xine, XINE_VERBOSITY_LOG,
+ "demux_mpgaudio: found Vbri header at offset %PRId64\n", frame_pos);
return 1;
}
}
@@ -707,39 +688,51 @@ static int demux_mpgaudio_next (demux_mpgaudio_t *this, int decoder_flags, int s
memcpy(&this->cur_frame, &this->next_frame, sizeof(mpg_audio_frame_t));
} else {
int bytes = 4;
+ int loose_sync = 0;
for (;;) {
if (!read_frame_header(this, header, bytes))
return 0;
if (parse_frame_header(&this->cur_frame, header)) {
- if (!this->has_ref_frame) {
- this->has_ref_frame = 1;
- memcpy(&this->ref_frame, &this->cur_frame, sizeof(mpg_audio_frame_t));
- lprintf("ref frame saved\n");
- } else {
- if (!check_frame_validity(this, &this->cur_frame)) {
- lprintf("invalid frame\n");
- bytes = 1; /* resync */
- continue;
- }
- }
lprintf("frame found\n");
- break;
- } else {
- lprintf("loose sync\n");
- if ( id3v2_istag(header) ) {
- if (!id3v2_parse_tag(this->input, this->stream, header)) {
- xprintf(this->stream->xine, XINE_VERBOSITY_LOG,
- LOG_MODULE ": ID3V2 tag parsing error\n");
- bytes = 1; /* resync */
+ /* additionnal checks */
+ if ((this->mpg_version == (this->cur_frame.version_idx + 1)) &&
+ (this->mpg_layer == this->cur_frame.layer)) {
+ this->valid_frames++;
+ break;
+ } else {
+ if (this->valid_frames > 3) {
+ lprintf("invalid frame. expected mpeg %d, layer %d\n", this->mpg_version, this->mpg_layer);
} else {
- bytes = 4;
+ this->mpg_version = this->cur_frame.version_idx + 1;
+ this->mpg_layer = this->cur_frame.layer;
+ this->valid_frames = 0;
+ break;
}
+ }
+ }
+
+ if (!loose_sync) {
+ off_t frame_pos = this->input->get_current_pos(this->input) - 4;
+ loose_sync = 1;
+ xprintf(this->stream->xine, XINE_VERBOSITY_LOG,
+ LOG_MODULE ": loose mp3 sync at offset %"PRId64"\n", frame_pos);
+ }
+ /* the stream is broken, don't keep info about previous frames */
+ this->free_bitrate_size = 0;
+
+ if ( id3v2_istag(header) ) {
+ if (!id3v2_parse_tag(this->input, this->stream, header)) {
+ xprintf(this->stream->xine, XINE_VERBOSITY_LOG,
+ LOG_MODULE ": ID3V2 tag parsing error\n");
+ bytes = 1; /* resync */
} else {
- /* skip */
- bytes = 1;
+ bytes = 4;
}
+ } else {
+ /* skip */
+ bytes = 1;
}
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-22 11:44:12 +0000