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; if (!avctx->sample_rate) avctx->sample_rate = fi.samplerate; if (fpc->pc->flags & PARSER_FLAG_USE_CODEC_TS){ fpc->pc->pts = fi.frame_or_sample_num; if (!fi.is_var_size) fpc->pc->pts *= 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); } /* 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; 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. */ /* buf_size is to zero when padding, so check for this since we do */ /* not want to try to read more input once we have found the end. */ /* Note that as (non-modified) parameters, buf can be non-NULL, */ /* while buf_size is 0. */ while ((buf && buf_size && read_end < buf + buf_size && fpc->nb_headers_buffered < FLAC_MIN_HEADERS) || ((!buf || !buf_size) && !fpc->end_padded)) { int start_offset; /* Pad the end once if EOF, to check the final region for headers. */ if (!buf || !buf_size) { 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 * 20) { /* There is less than one valid flac header buffered for 20 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_space(fpc->fifo_buf) < read_end - read_start && av_fifo_realloc2(fpc->fifo_buf, (read_end - read_start) + 2*av_fifo_size(fpc->fifo_buf)) < 0) { av_log(avctx, AV_LOG_ERROR, "couldn't reallocate buffer of size %"PTRDIFF_SPECIFIER"\n", (read_end - read_start) + av_fifo_size(fpc->fifo_buf)); goto handle_error; } if (buf && buf_size) { 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, (void*) 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) { int warp = fpc->fifo_buf->wptr - fpc->fifo_buf->buffer < MAX_FRAME_HEADER_SIZE; /* HACK: drain the tail of the fifo */ fpc->fifo_buf->wptr -= MAX_FRAME_HEADER_SIZE; fpc->fifo_buf->wndx -= MAX_FRAME_HEADER_SIZE; if (warp) { fpc->fifo_buf->wptr += fpc->fifo_buf->end - fpc->fifo_buf->buffer; } buf_size = 0; read_start = read_end = NULL; } } for (curr = fpc->headers; curr; curr = curr->next) { if (curr->max_score > 0 && (!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 buf_size ? read_end - buf : 0; }