Current aplay supports several types of data format for file; Microsoft/IBM RIFF/Wave (.wav), Sparc AU (.au) and Creative Tech. voice (.voc). These formats were designed to handle audio-related data with interleaved frame alignment.
This commit adds a common interface to handle the file format, named as 'container' module. This includes several functions to build/parse the format data from any file descriptors. Furthermore, this includes several helper functions for implementations of each builder/parser.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- axfer/Makefile.am | 7 +- axfer/container.c | 423 ++++++++++++++++++++++++++++++++++++++++++++++ axfer/container.h | 110 ++++++++++++ 3 files changed, 538 insertions(+), 2 deletions(-) create mode 100644 axfer/container.c create mode 100644 axfer/container.h
diff --git a/axfer/Makefile.am b/axfer/Makefile.am index 4e37b92..3913d0c 100644 --- a/axfer/Makefile.am +++ b/axfer/Makefile.am @@ -15,10 +15,13 @@ LDADD = \
noinst_HEADERS = \ misc.h \ - subcmd.h + subcmd.h \ + container.h
axfer_SOURCES = \ misc.h \ subcmd.h \ main.c \ - subcmd-list.c + subcmd-list.c \ + container.h \ + container.c diff --git a/axfer/container.c b/axfer/container.c new file mode 100644 index 00000000..77bbd6c --- /dev/null +++ b/axfer/container.c @@ -0,0 +1,423 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// container.c - an interface of parser/builder for formatted files. +// +// Copyright (c) 2018 Takashi Sakamoto o-takashi@sakamocchi.jp +// +// Licensed under the terms of the GNU General Public License, version 2. + +#include "container.h" +#include "misc.h" + +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <fcntl.h> + +static const char *const cntr_type_labels[] = { + [CONTAINER_TYPE_PARSER] = "parser", + [CONTAINER_TYPE_BUILDER] = "builder", +}; + +static const char *const cntr_format_labels[] = { + [CONTAINER_FORMAT_COUNT] = "", +}; + +static const char *const suffixes[] = { + [CONTAINER_FORMAT_COUNT] = "", +}; + +const char *const container_suffix_from_format(enum container_format format) +{ + return suffixes[format]; +} + +int container_recursive_read(struct container_context *cntr, void *buf, + unsigned int byte_count) +{ + char *dst = buf; + ssize_t result; + size_t consumed = 0; + + while (consumed < byte_count && !cntr->interrupted) { + result = read(cntr->fd, dst + consumed, byte_count - consumed); + if (result < 0) { + // This descriptor was configured with non-blocking + // mode. EINTR is not cought when get any interrupts. + if (cntr->interrupted) + return -EINTR; + if (errno == EAGAIN) + continue; + return -errno; + } + // Reach EOF. + if (result == 0) { + cntr->eof = true; + return 0; + } + + consumed += result; + } + + return 0; +} + +int container_recursive_write(struct container_context *cntr, void *buf, + unsigned int byte_count) +{ + char *src = buf; + ssize_t result; + size_t consumed = 0; + + while (consumed < byte_count && !cntr->interrupted) { + result = write(cntr->fd, src + consumed, byte_count - consumed); + if (result < 0) { + // This descriptor was configured with non-blocking + // mode. EINTR is not cought when get any interrupts. + if (cntr->interrupted) + return -EINTR; + if (errno == EAGAIN) + continue; + return -errno; + } + + consumed += result; + } + + return 0; +} + +enum container_format container_format_from_path(const char *path) +{ + const char *suffix; + const char *pos; + int i; + + for (i = 0; i < ARRAY_SIZE(suffixes); ++i) { + suffix = suffixes[i]; + + // Check last part of the string. + pos = path + strlen(path) - strlen(suffix); + if (!strcmp(pos, suffix)) + return i; + } + + // Unsupported. + return CONTAINER_FORMAT_COUNT; +} + +int container_seek_offset(struct container_context *cntr, off64_t offset) +{ + off64_t pos; + + pos = lseek64(cntr->fd, offset, SEEK_SET); + if (pos < 0) + return -errno; + if (pos != offset) + return -EIO; + + return 0; +} + +// To avoid blocking execution at system call iteration after receiving UNIX +// signals. +static int set_nonblock_flag(int fd) +{ + int flags; + + flags = fcntl(fd, F_GETFL); + if (flags < 0) + return -errno; + + flags |= O_NONBLOCK; + if (fcntl(fd, F_SETFL, flags) < 0) + return -errno; + + return 0; +} + +int container_parser_init(struct container_context *cntr, + const char *const path, unsigned int verbose) +{ + const struct container_parser *parsers[] = { + NULL, + }; + const struct container_parser *parser; + unsigned int size; + int i; + int err; + + assert(cntr); + assert(path); + assert(path[0] != '\0'); + + // Detect forgotten to destruct. + assert(cntr->fd == 0); + assert(cntr->private_data == NULL); + + memset(cntr, 0, sizeof(*cntr)); + + // Open a target descriptor. + if (!strcmp(path, "-")) { + cntr->fd = fileno(stdin); + err = set_nonblock_flag(cntr->fd); + if (err < 0) + return err; + cntr->stdio = true; + } else { + cntr->fd = open(path, O_RDONLY | O_NONBLOCK); + if (cntr->fd < 0) + return -errno; + } + + // 4 bytes are enough to detect supported containers. + err = container_recursive_read(cntr, cntr->magic, sizeof(cntr->magic)); + if (err < 0) + return err; + for (i = 0; i < ARRAY_SIZE(parsers); ++i) { + parser = parsers[i]; + size = strlen(parser->magic); + if (size > 4) + size = 4; + if (!strncmp(cntr->magic, parser->magic, size)) + break; + } + + // Don't forget that the first 4 bytes were already read for magic + // bytes. + cntr->magic_handled = false; + + // Unless detected, use raw container. + if (i == ARRAY_SIZE(parsers)) + return -EINVAL; + + // Allocate private data for the parser. + if (parser->private_size > 0) { + cntr->private_data = malloc(parser->private_size); + if (cntr->private_data == NULL) + return -ENOMEM; + memset(cntr->private_data, 0, parser->private_size); + } + + cntr->type = CONTAINER_TYPE_PARSER; + cntr->process_bytes = container_recursive_read; + cntr->format = parser->format; + cntr->ops = &parser->ops; + cntr->max_size = parser->max_size; + cntr->verbose = verbose; + + return 0; +} + +int container_builder_init(struct container_context *cntr, + const char *const path, enum container_format format, + unsigned int verbose) +{ + const struct container_builder *builders[] = { + NULL, + }; + const struct container_builder *builder; + int err; + + assert(cntr); + assert(path); + assert(path[0] != '\0'); + + // Detect forgotten to destruct. + assert(cntr->fd == 0); + assert(cntr->private_data == NULL); + + memset(cntr, 0, sizeof(*cntr)); + + // Open a target descriptor. + if (path == NULL || *path == '\0') + return -EINVAL; + if (!strcmp(path, "-")) { + cntr->fd = fileno(stdout); + err = set_nonblock_flag(cntr->fd); + if (err < 0) + return err; + cntr->stdio = true; + } else { + cntr->fd = open(path, O_RDWR | O_NONBLOCK | O_CREAT | O_TRUNC, + 0644); + if (cntr->fd < 0) + return -errno; + } + + builder = builders[format]; + + // Allocate private data for the builder. + if (builder->private_size > 0) { + cntr->private_data = malloc(builder->private_size); + if (cntr->private_data == NULL) + return -ENOMEM; + memset(cntr->private_data, 0, builder->private_size); + } + + cntr->type = CONTAINER_TYPE_BUILDER; + cntr->process_bytes = container_recursive_write; + cntr->format = builder->format; + cntr->ops = &builder->ops; + cntr->max_size = builder->max_size; + cntr->verbose = verbose; + + return 0; +} + +int container_context_pre_process(struct container_context *cntr, + snd_pcm_format_t *format, + unsigned int *samples_per_frame, + unsigned int *frames_per_second, + uint64_t *frame_count) +{ + uint64_t byte_count; + unsigned int bytes_per_frame; + int err; + + assert(cntr); + assert(format); + assert(samples_per_frame); + assert(frames_per_second); + assert(frame_count); + + if (cntr->type == CONTAINER_TYPE_BUILDER) + byte_count = cntr->max_size; + + if (cntr->ops->pre_process) { + err = cntr->ops->pre_process(cntr, format, samples_per_frame, + frames_per_second, &byte_count); + if (err < 0) + return err; + if (cntr->eof) + return 0; + } + + assert(*format >= SND_PCM_FORMAT_S8); + assert(*format <= SND_PCM_FORMAT_LAST); + assert(*samples_per_frame > 0); + assert(*frames_per_second > 0); + assert(byte_count > 0); + + cntr->bytes_per_sample = snd_pcm_format_physical_width(*format) / 8; + cntr->samples_per_frame = *samples_per_frame; + cntr->frames_per_second = *frames_per_second; + + bytes_per_frame = cntr->bytes_per_sample * *samples_per_frame; + *frame_count = byte_count / bytes_per_frame; + cntr->max_size -= cntr->max_size / bytes_per_frame; + + if (cntr->verbose > 0) { + fprintf(stderr, "Container: %s\n", + cntr_type_labels[cntr->type]); + fprintf(stderr, " format: %s\n", + cntr_format_labels[cntr->format]); + fprintf(stderr, " sample format: %s\n", + snd_pcm_format_name(*format)); + fprintf(stderr, " bytes/sample: %u\n", + cntr->bytes_per_sample); + fprintf(stderr, " samples/frame: %u\n", + cntr->samples_per_frame); + fprintf(stderr, " frames/second: %u\n", + cntr->frames_per_second); + if (cntr->type == CONTAINER_TYPE_PARSER) { + fprintf(stderr, " frames: %lu\n", + *frame_count); + } else { + fprintf(stderr, " max frames: %lu\n", + *frame_count); + } + } + + return 0; +} + +int container_context_process_frames(struct container_context *cntr, + void *frame_buffer, + unsigned int *frame_count) +{ + char *buf = frame_buffer; + unsigned int bytes_per_frame; + unsigned int byte_count; + int err; + + assert(cntr); + assert(!cntr->eof); + assert(frame_buffer); + assert(frame_count); + + bytes_per_frame = cntr->bytes_per_sample * cntr->samples_per_frame; + byte_count = *frame_count * bytes_per_frame; + + // Each container has limitation for its volume for sample data. + if (cntr->handled_byte_count > cntr->max_size - byte_count) + byte_count = cntr->max_size - cntr->handled_byte_count; + + // All of supported containers include interleaved PCM frames. + // TODO: process frames for truncate case. + err = cntr->process_bytes(cntr, buf, byte_count); + if (err < 0) { + *frame_count = 0; + return err; + } + + cntr->handled_byte_count += byte_count; + if (cntr->handled_byte_count == cntr->max_size) + cntr->eof = true; + + *frame_count = byte_count / bytes_per_frame; + + return 0; +} + +int container_context_post_process(struct container_context *cntr, + uint64_t *frame_count) +{ + int err = 0; + + assert(cntr); + assert(frame_count); + + if (cntr->verbose && cntr->handled_byte_count > 0) { + fprintf(stderr, " Handled bytes: %lu\n", + cntr->handled_byte_count); + } + + // NOTE* we cannot seek when using standard input/output. + if (!cntr->stdio && cntr->ops && cntr->ops->post_process) { + // Usually, need to write out processed bytes in container + // header even it this program is interrupted. + cntr->interrupted = false; + + err = cntr->ops->post_process(cntr, cntr->handled_byte_count); + } + + // Ensure to perform write-back from disk cache. + if (cntr->type == CONTAINER_TYPE_BUILDER) + fsync(cntr->fd); + + if (err < 0) + return err; + + if (cntr->bytes_per_sample == 0 || cntr->samples_per_frame == 0) { + *frame_count = 0; + } else { + *frame_count = cntr->handled_byte_count / + cntr->bytes_per_sample / + cntr->samples_per_frame; + } + + return 0; +} + +void container_context_destroy(struct container_context *cntr) +{ + assert(cntr); + + close(cntr->fd); + if (cntr->private_data) + free(cntr->private_data); + + cntr->fd = 0; + cntr->private_data = NULL; +} diff --git a/axfer/container.h b/axfer/container.h new file mode 100644 index 00000000..4a94d7f --- /dev/null +++ b/axfer/container.h @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// container.h - an interface of parser/builder for formatted files. +// +// Copyright (c) 2018 Takashi Sakamoto o-takashi@sakamocchi.jp +// +// Licensed under the terms of the GNU General Public License, version 2. + +#ifndef __ALSA_UTILS_AXFER_CONTAINER__H_ +#define __ALSA_UTILS_AXFER_CONTAINER__H_ + +#define _LARGEFILE64_SOURCE +#include <sys/types.h> +#include <unistd.h> + +#include <stdbool.h> +#include <stdint.h> + +#include <alsa/asoundlib.h> + +enum container_type { + CONTAINER_TYPE_PARSER = 0, + CONTAINER_TYPE_BUILDER, + CONTAINER_TYPE_COUNT, +}; + +enum container_format { + CONTAINER_FORMAT_COUNT, +}; + +struct container_ops; + +struct container_context { + enum container_type type; + int fd; + int (*process_bytes)(struct container_context *cntr, + void *buffer, unsigned int byte_count); + bool magic_handled; + bool eof; + bool interrupted; + bool stdio; + + enum container_format format; + uint64_t max_size; + char magic[4]; + const struct container_ops *ops; + void *private_data; + + // Available after pre-process. + unsigned int bytes_per_sample; + unsigned int samples_per_frame; + unsigned int frames_per_second; + + unsigned int verbose; + uint64_t handled_byte_count; +}; + +const char *const container_suffix_from_format(enum container_format format); +enum container_format container_format_from_path(const char *path); +int container_parser_init(struct container_context *cntr, + const char *const path, unsigned int verbose); +int container_builder_init(struct container_context *cntr, + const char *const path, enum container_format format, + unsigned int verbose); +void container_context_destroy(struct container_context *cntr); +int container_context_pre_process(struct container_context *cntr, + snd_pcm_format_t *format, + unsigned int *samples_per_frame, + unsigned int *frames_per_second, + uint64_t *frame_count); +int container_context_process_frames(struct container_context *cntr, + void *frame_buffer, + unsigned int *frame_count); +int container_context_post_process(struct container_context *cntr, + uint64_t *frame_count); + +// For internal use in 'container' module. + +struct container_ops { + int (*pre_process)(struct container_context *cntr, + snd_pcm_format_t *format, + unsigned int *samples_per_frame, + unsigned int *frames_per_second, + uint64_t *byte_count); + int (*post_process)(struct container_context *cntr, + uint64_t handled_byte_count); +}; +struct container_parser { + enum container_format format; + const char *const magic; + uint64_t max_size; + struct container_ops ops; + unsigned int private_size; +}; + +struct container_builder { + enum container_format format; + const char *const suffix; + uint64_t max_size; + struct container_ops ops; + unsigned int private_size; +}; + +int container_recursive_read(struct container_context *cntr, void *buf, + unsigned int byte_count); +int container_recursive_write(struct container_context *cntr, void *buf, + unsigned int byte_count); +int container_seek_offset(struct container_context *cntr, off64_t offset); + +#endif