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; int read_size = 0; if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { FLACFrameInfo fi; if (frame_header_is_valid(avctx, buf, &fi)) avctx->frame_size = 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. */ if (buf_size || !fpc->end_padded) { int start_offset; /* Pad the end once if EOF, to check the final region for headers. */ if (!buf_size) { fpc->end_padded = 1; buf_size = read_size = 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_size = FFMIN(buf_size, nb_desired * FLAC_AVG_FRAME_SIZE); } /* Fill the buffer. */ if (av_fifo_realloc2(fpc->fifo_buf, read_size + av_fifo_size(fpc->fifo_buf)) < 0) { av_log(avctx, AV_LOG_ERROR, "couldn't reallocate buffer of size %d\n", read_size + av_fifo_size(fpc->fifo_buf)); goto handle_error; } if (buf) { av_fifo_generic_write(fpc->fifo_buf, (void*) buf, read_size, NULL); } else { int8_t pad[MAX_FRAME_HEADER_SIZE]; memset(pad, 0, sizeof(pad)); av_fifo_generic_write(fpc->fifo_buf, (void*) pad, sizeof(pad), NULL); } /* Tag headers and update sequences. */ start_offset = av_fifo_size(fpc->fifo_buf) - (read_size + (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) 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 = read_size = 0; } } 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 frame_size to 0. It is unknown or invalid in a junk frame. */ avctx->frame_size = 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_size : (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_size; }