134 lines
3.9 KiB
C
134 lines
3.9 KiB
C
/*
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* Copyright (c) 2014 Stefano Sabatini
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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/**
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* @file libavformat AVIOContext read callback API usage example
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* @example avio_read_callback.c
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*
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* Make libavformat demuxer access media content through a custom
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* AVIOContext read callback.
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*/
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#include <libavcodec/avcodec.h>
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#include <libavformat/avformat.h>
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#include <libavformat/avio.h>
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#include <libavutil/file.h>
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struct buffer_data {
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uint8_t *ptr;
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size_t size; ///< size left in the buffer
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};
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static int read_packet(void *opaque, uint8_t *buf, int buf_size)
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{
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struct buffer_data *bd = (struct buffer_data *)opaque;
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buf_size = FFMIN(buf_size, bd->size);
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if (!buf_size)
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return AVERROR_EOF;
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printf("ptr:%p size:%zu\n", bd->ptr, bd->size);
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/* copy internal buffer data to buf */
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memcpy(buf, bd->ptr, buf_size);
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bd->ptr += buf_size;
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bd->size -= buf_size;
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return buf_size;
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}
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int main(int argc, char *argv[])
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{
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AVFormatContext *fmt_ctx = NULL;
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AVIOContext *avio_ctx = NULL;
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uint8_t *buffer = NULL, *avio_ctx_buffer = NULL;
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size_t buffer_size, avio_ctx_buffer_size = 4096;
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char *input_filename = NULL;
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int ret = 0;
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struct buffer_data bd = { 0 };
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if (argc != 2) {
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fprintf(stderr, "usage: %s input_file\n"
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"API example program to show how to read from a custom buffer "
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"accessed through AVIOContext.\n", argv[0]);
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return 1;
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}
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input_filename = argv[1];
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/* slurp file content into buffer */
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ret = av_file_map(input_filename, &buffer, &buffer_size, 0, NULL);
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if (ret < 0)
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goto end;
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/* fill opaque structure used by the AVIOContext read callback */
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bd.ptr = buffer;
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bd.size = buffer_size;
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if (!(fmt_ctx = avformat_alloc_context())) {
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ret = AVERROR(ENOMEM);
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goto end;
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}
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avio_ctx_buffer = av_malloc(avio_ctx_buffer_size);
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if (!avio_ctx_buffer) {
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ret = AVERROR(ENOMEM);
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goto end;
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}
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avio_ctx = avio_alloc_context(avio_ctx_buffer, avio_ctx_buffer_size,
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0, &bd, &read_packet, NULL, NULL);
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if (!avio_ctx) {
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ret = AVERROR(ENOMEM);
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goto end;
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}
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fmt_ctx->pb = avio_ctx;
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ret = avformat_open_input(&fmt_ctx, NULL, NULL, NULL);
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if (ret < 0) {
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fprintf(stderr, "Could not open input\n");
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goto end;
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}
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ret = avformat_find_stream_info(fmt_ctx, NULL);
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if (ret < 0) {
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fprintf(stderr, "Could not find stream information\n");
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goto end;
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}
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av_dump_format(fmt_ctx, 0, input_filename, 0);
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end:
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avformat_close_input(&fmt_ctx);
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/* note: the internal buffer could have changed, and be != avio_ctx_buffer */
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if (avio_ctx)
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av_freep(&avio_ctx->buffer);
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avio_context_free(&avio_ctx);
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av_file_unmap(buffer, buffer_size);
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if (ret < 0) {
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fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
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return 1;
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}
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return 0;
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}
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