static int get_best_header(FLACParseContext* fpc, const uint8_t **poutbuf,
int *poutbuf_size)
{
FLACHeaderMarker *header = fpc->best_header;
FLACHeaderMarker *child = header->best_child;
if (!child) {
*poutbuf_size = av_fifo_size(fpc->fifo_buf) - header->offset;
} else {
*poutbuf_size = child->offset - header->offset;
/* If the child has suspicious changes, log them */
check_header_mismatch(fpc, header, child, 0);
}
if (header->fi.channels != fpc->avctx->channels ||
!fpc->avctx->channel_layout) {
fpc->avctx->channels = header->fi.channels;
ff_flac_set_channel_layout(fpc->avctx);
}
fpc->avctx->sample_rate = header->fi.samplerate;
fpc->pc->duration = header->fi.blocksize;
*poutbuf = flac_fifo_read_wrap(fpc, header->offset, *poutbuf_size,
&fpc->wrap_buf,
&fpc->wrap_buf_allocated_size);
fpc->best_header_valid = 0;
/* Return the negative overread index so the client can compute pos.
This should be the amount overread to the beginning of the child */
if (child)
return child->offset - av_fifo_size(fpc->fifo_buf);
return 0;
}
static int find_headers_search_validate(FLACParseContext *fpc, int offset)
{
FLACFrameInfo fi;
uint8_t *header_buf;
int size = 0;
header_buf = flac_fifo_read_wrap(fpc, offset,
MAX_FRAME_HEADER_SIZE,
&fpc->wrap_buf,
&fpc->wrap_buf_allocated_size);
if (frame_header_is_valid(fpc->avctx, header_buf, &fi)) {
FLACHeaderMarker **end_handle = &fpc->headers;
int i;
size = 0;
while (*end_handle) {
end_handle = &(*end_handle)->next;
size++;
}
*end_handle = av_mallocz(sizeof(**end_handle));
if (!*end_handle) {
av_log(fpc->avctx, AV_LOG_ERROR,
"couldn't allocate FLACHeaderMarker\n");
return AVERROR(ENOMEM);
}
(*end_handle)->fi = fi;
(*end_handle)->offset = offset;
(*end_handle)->link_penalty = av_malloc(sizeof(int) *
FLAC_MAX_SEQUENTIAL_HEADERS);
if (!(*end_handle)->link_penalty) {
av_freep(end_handle);
av_log(fpc->avctx, AV_LOG_ERROR,
"couldn't allocate link_penalty\n");
return AVERROR(ENOMEM);
}
for (i = 0; i < FLAC_MAX_SEQUENTIAL_HEADERS; i++)
(*end_handle)->link_penalty[i] = FLAC_HEADER_NOT_PENALIZED_YET;
fpc->nb_headers_found++;
size++;
}
return size;
}
static int flac_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
FLACParseContext *fpc = s->priv_data;
FLACHeaderMarker *curr;
int nb_headers;
const uint8_t *read_end = buf;
const uint8_t *read_start = buf;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
FLACFrameInfo fi;
if (frame_header_is_valid(avctx, buf, &fi))
s->duration = fi.blocksize;
*poutbuf = buf;
*poutbuf_size = buf_size;
return buf_size;
}
fpc->avctx = avctx;
if (fpc->best_header_valid)
return get_best_header(fpc, poutbuf, poutbuf_size);
/* If a best_header was found last call remove it with the buffer data. */
if (fpc->best_header && fpc->best_header->best_child) {
FLACHeaderMarker *temp;
FLACHeaderMarker *best_child = fpc->best_header->best_child;
/* Remove headers in list until the end of the best_header. */
for (curr = fpc->headers; curr != best_child; curr = temp) {
if (curr != fpc->best_header) {
av_log(avctx, AV_LOG_DEBUG,
"dropping low score %i frame header from offset %i to %i\n",
curr->max_score, curr->offset, curr->next->offset);
}
temp = curr->next;
av_freep(&curr->link_penalty);
av_free(curr);
fpc->nb_headers_buffered--;
}
/* Release returned data from ring buffer. */
av_fifo_drain(fpc->fifo_buf, best_child->offset);
/* Fix the offset for the headers remaining to match the new buffer. */
for (curr = best_child->next; curr; curr = curr->next)
curr->offset -= best_child->offset;
fpc->nb_headers_buffered--;
best_child->offset = 0;
fpc->headers = best_child;
if (fpc->nb_headers_buffered >= FLAC_MIN_HEADERS) {
fpc->best_header = best_child;
return get_best_header(fpc, poutbuf, poutbuf_size);
}
fpc->best_header = NULL;
} else if (fpc->best_header) {
/* No end frame no need to delete the buffer; probably eof */
FLACHeaderMarker *temp;
for (curr = fpc->headers; curr != fpc->best_header; curr = temp) {
temp = curr->next;
av_freep(&curr->link_penalty);
av_free(curr);
}
fpc->headers = fpc->best_header->next;
av_freep(&fpc->best_header->link_penalty);
av_freep(&fpc->best_header);
}
/* Find and score new headers. */
while ((buf && read_end < buf + buf_size &&
fpc->nb_headers_buffered < FLAC_MIN_HEADERS)
|| (!buf && !fpc->end_padded)) {
int start_offset;
/* Pad the end once if EOF, to check the final region for headers. */
if (!buf) {
fpc->end_padded = 1;
buf_size = MAX_FRAME_HEADER_SIZE;
read_end = read_start + MAX_FRAME_HEADER_SIZE;
} else {
/* The maximum read size is the upper-bound of what the parser
needs to have the required number of frames buffered */
int nb_desired = FLAC_MIN_HEADERS - fpc->nb_headers_buffered + 1;
read_end = read_end + FFMIN(buf + buf_size - read_end,
nb_desired * FLAC_AVG_FRAME_SIZE);
}
if (!av_fifo_space(fpc->fifo_buf) &&
av_fifo_size(fpc->fifo_buf) / FLAC_AVG_FRAME_SIZE >
fpc->nb_headers_buffered * 10) {
/* There is less than one valid flac header buffered for 10 headers
* buffered. Therefore the fifo is most likely filled with invalid
* data and the input is not a flac file. */
goto handle_error;
}
/* Fill the buffer. */
if (av_fifo_realloc2(fpc->fifo_buf,
(read_end - read_start) + av_fifo_size(fpc->fifo_buf)) < 0) {
av_log(avctx, AV_LOG_ERROR,
"couldn't reallocate buffer of size %td\n",
(read_end - read_start) + av_fifo_size(fpc->fifo_buf));
goto handle_error;
}
if (buf) {
av_fifo_generic_write(fpc->fifo_buf, (void*) read_start,
read_end - read_start, NULL);
} else {
int8_t pad[MAX_FRAME_HEADER_SIZE] = { 0 };
av_fifo_generic_write(fpc->fifo_buf, pad, sizeof(pad), NULL);
}
/* Tag headers and update sequences. */
start_offset = av_fifo_size(fpc->fifo_buf) -
((read_end - read_start) + (MAX_FRAME_HEADER_SIZE - 1));
start_offset = FFMAX(0, start_offset);
nb_headers = find_new_headers(fpc, start_offset);
if (nb_headers < 0) {
av_log(avctx, AV_LOG_ERROR,
"find_new_headers couldn't allocate FLAC header\n");
goto handle_error;
}
fpc->nb_headers_buffered = nb_headers;
/* Wait till FLAC_MIN_HEADERS to output a valid frame. */
if (!fpc->end_padded && fpc->nb_headers_buffered < FLAC_MIN_HEADERS) {
if (buf && read_end < buf + buf_size) {
read_start = read_end;
continue;
} else {
goto handle_error;
}
}
/* If headers found, update the scores since we have longer chains. */
if (fpc->end_padded || fpc->nb_headers_found)
score_sequences(fpc);
/* restore the state pre-padding */
if (fpc->end_padded) {
/* HACK: drain the tail of the fifo */
fpc->fifo_buf->wptr -= MAX_FRAME_HEADER_SIZE;
fpc->fifo_buf->wndx -= MAX_FRAME_HEADER_SIZE;
if (fpc->fifo_buf->wptr < 0) {
fpc->fifo_buf->wptr += fpc->fifo_buf->end -
fpc->fifo_buf->buffer;
}
buf_size = 0;
read_start = read_end = NULL;
}
}
curr = fpc->headers;
for (curr = fpc->headers; curr; curr = curr->next)
if (!fpc->best_header || curr->max_score > fpc->best_header->max_score)
fpc->best_header = curr;
if (fpc->best_header) {
fpc->best_header_valid = 1;
if (fpc->best_header->offset > 0) {
/* Output a junk frame. */
av_log(avctx, AV_LOG_DEBUG, "Junk frame till offset %i\n",
fpc->best_header->offset);
/* Set duration to 0. It is unknown or invalid in a junk frame. */
s->duration = 0;
*poutbuf_size = fpc->best_header->offset;
*poutbuf = flac_fifo_read_wrap(fpc, 0, *poutbuf_size,
&fpc->wrap_buf,
&fpc->wrap_buf_allocated_size);
return buf_size ? (read_end - buf) : (fpc->best_header->offset -
av_fifo_size(fpc->fifo_buf));
}
if (!buf_size)
return get_best_header(fpc, poutbuf, poutbuf_size);
}
handle_error:
*poutbuf = NULL;
*poutbuf_size = 0;
return read_end - buf;
}